Souldn't be a huge job to transplant a CVH lump into a mk6 as I'm sure they fitted the 1.4 CVH lump in them, maybe just need to change the mounts.

Best bet would be to buy an RST with a shit body or crash damaged rear and strip all the bits.

Cars for sale has a S2 for £750 which should have everything you need and will be 10 x cheaper than sourcing parts, plus you can put the 2 cars side by side to work on, rip out the zetec stuff then move the parts over.

The majority of the work you could do yourself, may need an auto electrician to sort the loom out for you.

You dont say where in the country you are, may be tuners or specialist near you that can do the job for you, just dropp the 2 cars off. Plus you can seel all the left over parts from both cars and recoop cash fromn the job so may end up costing you vurtually nothinbg at all

I would imagine turboing a zetec will be massively more to do.

Matt