New Ultima GTR Chassis bought. What specs to get?

[UltimaDean]

Hi. I've ordered my chassis, double skin kit, what should I get next?
I am thinking AP brakes, LS7 engine, leather interior, ultima clocks for some specs.
I haven't thought about the gearbox.
Where am I best going for the engine, ultima suggest American Speed, any suggestions? Gearbox? Help please.

[UltimaDean]

Thanks Guys. I've had a quick look over the build manual, and yes it is a little bit shallow. I think some of these other Ultima build sites are much clearer. I'll let you know how things are getting on. And believe me I think there'll be many questions I'll be asking. As for the hints please keep them coming I'm writing it all down.