deffo go 2.0 silvertop with the RS1800 spec inlet side of things mate, as per our pm's and what twins said....as long as you get all the 130 spec stuff its the best out of the 3 in my opinion.

RS2000 engine bolts straight up to S2 box but rear mount takes a bit more work, plus you need to suss out an alternator set-up. Not sure its worth the extra aggro over the Zetec, however the I4 sounds mint