A37 or A57 with 18-135

Ok. I really want the 18-135 lens but am wondering if the a37 will suffice over the a57 for a price difference of $200. I'm new to dslr photography but really want to learn how to successfully use one. I'd like to eventually move into photographing other people's kids and portraits. I'm wondering if the new sony releases next year will include better high iso/low light. So should i wait? I know I'd have to move up to a better body eventually. I'd love the a77 but its over my budget. Anyone have any thoughts? I'd also like to get a 35mm prime as well. Thanks.