http://www.jimhearne.co.uk/zvh.htm is a good site.

Obvoisly the spec of the engine will depend on how much it would cost.

I'd say anything from £2000 up to £7000 (depending on spec and how much work you do yourself).

I think mine has stuck me in about £6500 including All new parts, accralite pistons, copper head gasket, T34 turbo etc (however i've done most of the work myself).
My management was about another £1800 on top of that.

Matt.