Hi Andy, for Torch I would suggest the vented shock caps so you can run the shocks in emulsion set up, smoothes the car out over the bumps quite a lot.
The front alloy upper transmission housings a good to have for strength but not essential first off. I also use the alloy rear camber link on my K1 and KF2.
A 7.5 or 6.5 would be good motor wise, can't remember gearing but I expect something like a 22t pinion would be a good starting point for a 6.5.
Let me know how you get on, I'm getting mine delivered to where I'm working at the moment (Isle of Islay) and will build here. Look forward to seeing you at Torch and Newbury in December when I get home.
Rich Roberts