... Slip a new clutch on a A12?

Today while road testing going up a steep hill on 18 pounds the revs built and the car didn't move - guess the clutch started to slip! This really bummed me because I dont abuse clutches (unless 18psi counts lol) - I dont do burnouts or launch the car and today even though it pulls mega hard the accel. felt a bit flat and up a hill it was obvious the clutch is slipping!

So does anyone know of a good replacement? Any specific brand names come to mind other than exedy?

Although I turboed my engine myself (built the manifolds/pipes/exhaust/connected it all up and tuned it) im actually clueless about the clutch!

Does anyone have any idea how I'd go about it with leaving the engine in. I do have a HD floor jack on wheels and jack stands if that helps - I can buy some car ramps if needed too?!

I was looking at rebuild the gearbox (4spd) or finding a 5 speed too - I guess this is a good time for it?

Some pointers would be awesome!