I was in your same situation last year. Any decent chassis will do, just decide if you are ok with buying all parts over the Inet or like going to a store. I chose the Inet route and run a 8 year old TC in 17.5 and believe me, the car is not the slow part of the equation
I made life simple and gave myself the most options until I could decide on what TC class to run: Tekin RS and Redline motor combo with 2 good LiPo batteries, and a good charger. I 'borrowed' an older HiTec 625MG servo from my XXX-T and it works great onroad. Also, the Tekin speedo is not as hard to get setup as some say. Start with a good basic setup - available on a thread in the forum, or ask Tekin support directly. Tekin users (well, most of them) are really helpful. Ok, ok, so you do need a laptop to tweak it. To be honest, now that I have a good setup I just change gearing and don't bring the laptop to every race.
This setup has performed very well with NO crazy maintenance hassles. Strap in the batt and go have fun!!!