my dads got a 2ltr zetec in his dax rush on throttle bodies.

he's got dunnell stuff on his.
not sure on the prices but the people there are pretty good.
out of the box the kit gives 175bhp.
only internal mod is uprated rod bolts.

he had that for a while and then spent a bit more money and got the dunnell cams also.
this along with raising the rev limiter to 7200 gives his 215bhp.
and 20 quid in petrol still gets him about 170 miles.

http://www.dunnellengines.com

that is their website