It depends. In the US most mail-order hatcheries offer you the option of vaccination so you get to decide. I do not know what Rochester hatchery (the only Canadian mail-order 'real hatchery' I know of, unless you consider Performance to be a real hatchery) does, if you are thinking of ordering from them then I would suggest looking at their website or calling them. If you buy chicks from the local feedstore, though, as most people would do for just a few CornishX, you will not likely get a choice about vaccination... you should ask at the feedstore, if it matters to you.
(Personally I am really unconvinced that Mareks vaccination is a big deal one way OR the other, unless you know you've had problems with a serious strain of Mareks in your flock in the past in which case I think vaccinating is sensible)
Also any chance you'd want to suggest a breed of broiler for me to try. Is it at all possible to get birds that are not super bred to be huge and meaty? The documentary Food Inc. stands out in my mind where the farmer said "why raise a bird in 90 days when I can do it in 42 with hormones". These birds were so heavy they couldn't stand on their own feet because they grew so fast their bones hadn't developed properly and were dying of heart attacks. My intention of doing this was to avoid franken food but you are saying regardless their life span is still only 6 weeks?
Well, you are unlikely to have much of a choice. Basically your main choice for meaties is the CornishX (broiler chicks) your feedstore sells.
My feedstore also carries what they call "red broilers", which are not quite as sumo-esque or quick-growing as the CornishX but as long as you are not looking for a super large carcass I have been quite satisfied with them (interestingly, they seem to give me almost exactly the same net feed conversion efficiency to time of slaughter, at least to a 4-5 lb slaughter weight, it just takes them longer to get there, but they do not eat as 'intensely' as the CornishX). However the ones my feedstore carries are an Ontario hatchery product and I have noooooo clue whatsoever what's available to you out in Alberta. Check the Rochester catalog (if you would mail-order) or ask around at local feedstores.
Really, though, those are your only true meat-bird choices. (I do not believe Freedom Rangers or similar are available in Canada these days).
My experience with CornishX and the red broilers has not been as grim as commercial broiler barn statistics would suggest... I have not lost a single one (yet), but I attribute this partly to luck and largely to THEY HAVE LOTS OF ROOM AND REASON TO EXERCISE. I have processed them between 5-9 weeks of age, depending on size and ambition and my schedule. The 9 wk CornishX were scary enough that I would not want to have tried to grow them out much if any more, but there also is not much POINT in it since by then you are shovelling vast quantities of food into them for very, very little extra weight gain.
Your other option would be to raise a regular dual-purpose bird (preferably something fairly quick-growing and meaty-conformation, as dual purpose breeds go) that you would grow up to maybe 14 wks if you want a 3-ish lb cleaned carcass, or up to maybe 20 wks if you want a 4-4.5-ish lb cleaned carcass. This is MUCH MORE EXPENSIVE than raising meat birds however, because the feed conversion efficiency is FAR lower, also the carcass weight has a substantially higher fraction of bone and other waste than in a CornishX. Basically it is a different type of product altogether -- tastier, firmer meat, needs to be cooked somewhat differently than you may be used to with supermarket chicken meat, and much less meat per carcass. I really LIKE 'real chicken'
best, mind you, but you need to be aware that if you want economic efficiency (cost to produce 1 lb of meat) or a big meaty carcass, actual broiler strains would the way to go.
I think I might try a turkey or two as well. Go big or go home!
I would suggest several, they are very social and beyond the first few months you may find you need to separate them from the chickens as the size difference can become a problem even if they don't really *mean* to hurt anyone. Although some people do raise turkeys and chickens in the same pen without problems, and if they are free-ranging (and don't get et by predators) there is much less of an issue.
Bear in mind that one turkey poos about as much as maybe 6-8 chickens, so they will stink to high heaven unless you give them a LARGE area
If you want to try turkeys, I would suggest getting maybe 3 poults from the feedstore at the same time as you get your meat chicks. They can live together for the first weeks, so the chicks can teach the poults how to eat and drink. Feedstore turkeys will be the commercial (broadbreasted) strains, that are more or less the turkey equivalent of CornishX, so do not necessarily count on making htem pets or keeping them past 5-6 months or so as by that time they can be seriously outweighing their legs or cardiovascular systems. It would normally be something on the order of 4 months til you would process them, depending on what size carcass you want of course (as with broiler chickens, feed conversion efficiency deteriorates faster and faster the bigger and older they get, so it is a tradeoff).
Alternatively you can get 'real' turkeys, heritage-breed, but you will pay at least twice as much for the poults, you will need at least 6 months before processing them, and not only will they finish at a much smaller weight than the broadbreasted commercial strains they will also have a lot less meat for whatever the carcass weighs (the more 'picturesque' heritage breeds especially... IME beltsville small whites and ridley bronzes have at least been *somewhat* selected for carcass qualities, whereas things like royal palms or these narragansetts I got last year and have pretty much given up on, they are mostly bone and tendon for what the carcass weighs)
Or, perhaps just do meat chickens this year, see how you like them and get used to the chick thing, then next year try a few turkeys.
Good luck, have fun,
Pat