I've been shooting with a xti for over two years. This past year, friends have started paying me to take pictures of their kids and families. I'm ready to upgrade and have about $1200 to spend. The lens I use most is the 24-105mm L. I do have a 50mm 1.8, but I don't think the image quality is as good as the 24-105. I'm looking for a something that has a better ISO and viewfinder. I don't care about video at all. Which Canon would you suggest I invest in? I'm open to other suggestions too.