There are a lot of great chassis out there any one of which will work well for you. Mainly it will depend on what you like. Look at BMI Racing, Team Associated, Team CRC, Serpent, Xray, Speed Merchant, and tons of other brands out there I can't think of off hand. I assume you plan to race at a local track? If so your best bet would be to find out what brands of 1/12th scales they stock parts for. Otherwise you'll be waiting on the mail every time you break something. Personally my favorite right now is the BMI DB12RR but that is because I'm biased and drive that car
There is a 1/12th thread...it's really long though so you'll never have time to read the whole thing. But I would advise at least skimming it and see what catches your attention.