I've posted on this before, but I have a few more questions. I'm building a 6ft W x 8ft L tractor. My main problem is how to attach wheels to the structure. I am thinking of using wheelbarrow wheels because I DO NOT want to build a trailer. Anyone have a suggestion? I'd love some advice. Secondly, when I first posted about this coop, it was going to be 5 x 8 and hold around 10 birds. Will the extra foot of width mean a few extra birds?