Advice: 1st Gen Nitro RS4 RTR

Hello all,
Last spring I dusted off my old HPI Nitro RS4 RTR. I stopped running it because the idle screw broke off in the carb and the barrel kept sliding out. I bought a an HPI T3.0 and installed it. After a few broken parts and melted gears (lots of power!) I got it set right and running fairly good. Heres are all the improvements I've done...

- T3.0 Engine (can anyone tell me what the HP rating is on this? can't find it)
- Lightweight flywheel
- All new bearings
- New rear diff
- Replaced front bumper, spur gear, brake disk, belts, and have a new chassis on the way

My question is how can I get the most out of this new engine in this car? I can't find the 2-speed tranny anywhere, so thats out.

I considered buying a new kit and putting the electronics and engine in that, but all the HPI kits are RTR now. I've considered the Team Associated TC3 Factory Team Kit but I'm not sure if my engine will fit correctly in it and its a little pricey. Are there any good kits I can get that come without electronics and engine? Or should I stick with the RS4? Any advice would be greatly appreciated!