Tamiya makes the DF03ra chassis which is specifically for rally purpose, that could work for what you're thinking about. Here's a link.
http://www3.towerhobbies.com/cgi-bin...&I=LXWXX9&P=SM
Of course there's also the Kyosho Inferno GT with the Subaru body, they can go insanely fast once converted to brushless, I know, I have one but that's 1/8 scale.
Also there's a crap load of hop-ups for the DF03ra on RCmart.com. You can use most of the hop-ups made for the DF03 also as this is the exact chassis the DF03ra is using, the only difference is the shocks/towers are shorter.