There's a 2litre 16valve 'Redtop' in a Calibra and a 2litre 8valve in another Calibra at a place called Dixons on Cleveland Street in B'Head. They said 350 quid for just the block for the Redtop, so I'd say half that for the 8valve.
On top of that you'd need:
Cone airfilter (no space)
Relay board for Fuel pump relay
I'd advise you change the gearbox though, the one in the Nova wouldn't last long, and the driveshafts have more splines, so you'll need two of them (I have two spare). The linkages are the same.
And if that weren't enough, you should get the engine bay seam welded, you'll start to notice little spaces in the bay if you don't.
I think that's it, but I'm nay sure about new engine mounts though.
I'll speak you on MSN when I'm not in crappy work.