The Outfit who 'specialise' in engines fit cast (hypereutectic) pistons
which were designed for the american 1.9 cvh which was never
treated to forced induction in it's home market.
These have the unfortunate habit of turning to chocolate when
running 8psi.
If you read their site carefully they 'get round' this one by lowering
the compression (kinda defeats the point)and invalidating their
warranty if you raise the boost above 7psi.
The other 'gentlemen' no longer build engines you'll hear allsorts about their
engine builder developing a dodgy back (he put cast pistons in his 1.9's
as well)so they no longer build engines.Back or too many warranty claims
due to crap engineering/you decide. They will however be happy to
steer you in the direction of another expert in West London who'll also
take 700 beer tokens off you for a set of the above dairy milk pistons.