One thing I would warn you about with your plan.....though it sounds like a good plan to not get them till warmer weather it will probably cause you problems later on depending on what breed you get. The classic 'meaty' is a Cornish/white Rock cross usually called a cornish cross (CX) or cornish rock, these birds grow incredibly fast and are usually ready for butcher between 7-10 weeks. The big problem is that they don't deal well with hot weather. I would strongly recommend having them butchered before mid June or not getting them till late summer with the plan to butcher them in October instead. They are prone to heart and bone problems due to their growth rate and they can just drop over dead with little warning and it seems worse in hot weather.
There are alternative meat birds which grow slower and aren't as rotund as the CX, you would be feeding them for 14-18 weeks (depending on strain) and they behave much more like your normal back yard chickens. They have fewer health issues, but will have less meat (especially breast meat) so your feed bill conversion to meat produced would be lower, though they will forage for some of their food, so that can help. These birds are often called 'freedom rangers' , red rangers or black rangers. Most hatcheries have a version of these birds and it will explain their differences usually on their info guides. The rangers can be raised with much less concern over weather.
Meaties don't need a full 'coop' but they do require the same protection from wind, rain and damp ground. Tractors are a good answer for them and moving it frequently will help with odor/cleaning issues also. Meaties can't roost like normal birds, they would break their legs jumping even a foot or two to the ground and their balance tends to be horrible so they are better with very low roosts such as 2x4's only a few inches off of the ground or even just a soft bed of hay (which would have to be changed out frequently) Meat birds do need heat the first couple of weeks but we have found that if you have more than a dozen of them they need much less heat than normal chicks would. It just seems they grow so fast and put off a lot of body heat. We had ours outside last year in 38-40* weather with a single heat lamp in their nesting area when they were 3 weeks old (protected from rain and wind but not in an insulated coop or anything like that) We just partitioned off their 'nesting area' to further protect it from the elements and help it to retain heat. They would lounge under the light at night and for periods of time during the day but roam out for food and water frequently.
So in our experience, meaties are a great thing, but they are better suited to spring and fall for our preferred breed (the CX). If we had more 'pasture' available I think the rangers would be a good choice for simpler keeping if we didn't want the breast meat/white meat as much.
I found my Mr Spock dead this morning. I was so upset 
Fat chance...
hard to see but she's an all black (skin and all) silkie/marans mix
