Feck - after spending all that dough dude.... feel your pain, I'd be truly gutted! Whilst I'm sure this is of no help whatsoever, custom builds of this level was the main reason I avoided building my VQ and swapping to V8.
I'm also no mechanic, but you're continuously repairing this damn car dude, get shot of it, you're already knee deep in build costs and it doesn't sound like it's getting any better. Forking out on a built engine and now this.... mate seriously I'd be looking at throwing the towel in.