Wish I could help more but the only answer I have is you need a spigot bearing for a v6 xr 4x4 but if your engine has been mated to a manual box this will be fitted.
I'd use the standard clutch,the 1 I built years ago had a standard clutch and it coped no bother.
Wiring was a pain but if it's the earlier non pats loom it's easier to wire in.
Dojj or fitz at top boss performance will be the people I'd ask.