If keeping below 500bhp then use standard MAHLE, these are VERY underated.
I am sure MAHLE 2wd psitons have been deleted, and only the 4wd "type" are offered which basically have a minute difference in wrist pin/gudeon pin offset so eliminating piston slap, they do a 7.9:1 and a 8.0:1 CR in the various oversizes, as it will alter CR MINUTELY not enough to cause any problem.
These are FORGED, and can be obtained from the likes of Matt Lewis 01922 692424.
The main difference apart from a slighht difference in CR between 2/4wd is the offset of the wrist pin due to a lot of 2wd having piston slap, which although harmless was not desired by ford, mine(2wd) sounds like a tractor when cold!!
tabetha