If you really want a 45acp for carry---don't rule it out. I carry the mid size Glock very well in jeans and t-shirt, I just don't like wearing shorts (ugly white bird legs). I had been seriously working with my SIG P220 SAO and MTac Minotaur holster for the summer time carry, and If I had a bit more girth-it would be very possible and comfortable. The old saying "where there's a will, there's a way" should be viable for most, but there are limitations. Alot of 1911 model manufacturers now make very small 'carry' options comparative to their larger counterparts. Being the revolver fan you are, a 6 or 7 shot baby 1911 might well be a good alternative. The Glock G36 would be in the mix as well as maybe the G30 or 30sf (10 round capacity) in the 45's as well. If you absolutely cannot go in the larger caliber of your choice, then by all means go for the highest capacity possible in the alternatives.
I don't think I can carry a 45 and be comfortable.