Yes, Zetec bolted to a TC bellhousing which is bolted to an NG3. You might be able to squeeze a compressor on the exhaust side but how you would do that would be up to you. As for the chassis, it's all fabricated, there's no stock chassis in it at all.
In regards to Zetec HP, I would guess that anything over 190ish NA HP requires a lot of work and wouldn't be very "peaky" (been there done that with warmed up 4AG in a Seven, tons of fun at WOT but around town it was bit much). I'm sure you could get something close to 250 with a turbo. IMHO you dont need much more than 180 HP in a Europa, they're a fairly light car so don't need a lot of power.