pocket rocket gas remote control car?

witch one should i get

Ok, before i launch into an answer, have you ever used nitro powered RC vehicles? 'Cos if not, i would strongly advise getting a electric powered car to start. Electric is so much easier and cheaper to maintain, and with brushless motors, not as slow as it used to be.
I have http://www.nitrotek.co.uk/A2010T.htm and i love it, does at least 35 mph on tarmac.
However, if your adamant about wanting nitro there are a load of different options. If you want small and cheap as chips, go for; http://www.nitrotek.co.uk/A3010T.htm

If you want something a little bigger and more expensive try; http://www.traxxas.com/products/nitro/nsport4510/trx_nsport4510.htm

If you want something very up-market; http://www.losi.com/Products/Default.aspx?ProdID=LOSB0085 is something ive heard very good things about.

There is alot to chose from, and depends entirely on your budget, skill, and space. Information which is sadly lacking.