cheers cossiecrew

best ppl to speak to about this type of conversion are van aiken (sp) they do this conversion off the shelf for fiestas

i think even with a t25 you would need a cooler as the fiesta turbo uses pretty much the same setup as you suggest

I also think the s2 manifold wont mate to a t25 turbo, dont quote me on that tho

for my conversion I have used new pistons etc to lower the compression, a s2 manifold with a stg 1 t3 turbo, ive also used a 4x4 saph cos intercooler. this is all run with a OFAB fiesta turbo ignition loom and ecu.

standard machined pistons I have been told are only OK to about 10psi which would probably be fine in your case.

also the standard zetec inlet manifold will probably struugle to supply enough fuel, so either a change of inlet is needed or a mapped fifth injector run off a unichip perhaps incorporating a map sensor to run and control the turbo

HTH

Click ma sig for a look at my own turbo project which is very nearly finished. the price for mine is vastly higher than what yours would be, as its been done totally different.