Ready to go outside????

The girls turn 4 weeks tomorrow. They are definitly getting growing bigger by the day!! I have RI Reds, Barred Rocks, a Dominique, and a buff cochin. I have noticed that a few of the 14 arent as big as some of the others, but are growing, and 1 of the RIR's is bigger than the rest. Does this mean anything? I believe all were born the same day. Now the main question, I will be keeping 10 of the chicks, 4 are going to a friend. I previously posted as to whether or not my coop was big enough, and it seems it was kind of on the fence so saturday ill be adding a 42"x36" addition. I am in CT and the nights have been around mid 30s, days in the 50s. Their indoor pen has been around 82 degrees. Im wondering if another week or 2 if they will be ready to be moved outside, and if so should i do a heat lamp on a timer for night time(i was thinking a smaller wattage bulb, smaller then the 250s since the coop is enclosed and all)? are they old enough yet? or should i wait til the 8 week mark? and lastly, at what age to i start feeding them the next step up in feed? Thanks for all the help!!!

In the "old timers" tread (I'll see if I can dig it up) one of the people who had been keeping chickens forever said that all his/her chicks go outside at 3 weeks, no matter what. Which surprised me, but if you think about it, 100 years ago you can pretty well bet people weren't keeping baby chickens in the house by the fire for months on end. So, there's that.

Found it. Well, the thread at least. Good luck finding that post!

SOUNDS GOOD THANKS!!!