I would go full zetec, you will only need a standard head with devil developments valve springs too run upto 400bhp

I don't know what everyone above is going on about, yes the rs1600i head has the best design in standard form, but you will need a fully modified big valve head too make the most of your bottom end and turbo, the rs1600i head isn't as good as others modified as it can't take valves as large as others

So you will need a xr2i efi head or a crosshatch style head, crosshatch can take 44mm valves and xr2i efi ones have been known too have 45mm valves

Search on google for "puma race engines cvh tuning guide" and this has all the info on heads and which one too choose and why

P.s for a Zvh you will need
Zvh conversion parts
Newman cam (Zvh grind)
Double valve springs
Solid lifters
Head ported
Bigger valves
Ect ect and this will triple the price of fitting the zetec head and valve springs

But it's upto you mate as it's your car, and good results can still be had from a Zvh (500bhp+) but the cvh eats camshafts for a living these days

I would speak too sitech racing as above or jamsport on the Zvh front, or devil developments for zetec turbos and try and find all the pros and cons

For me personally I would go Zvh if I was just changing a bottom end on a mfi car but if going efi it's a lot cheaper too go full zetec and get more power and torque