Brake caliper rebuild

[byakk0]

I asked this in my rebuild thread, but it will probably get more exposure as a stand-alone question, so here goes.

Before I buy new or reconditioned calipers, I am going to rebuild the ones I have first. They are 16P GT6 calipers.
What experience does anyone have any with aftermarket brake pistons?
James paddock has a good price, and with other parts I will need, should I buy from them I'll get the pistons as well.
http://www.jamespaddock.co.uk/parts.aspx?categoryID=22&vehicleId=4
(P type caliper, part 510792)

Some available from other vendors are steel, stainless, and nitride coated steel. The stainless look to be the most expensive, and I have heard the cheaper ones rust quickly.

[junkuser]

Originals most likely chrome plated steel, well they were on early Spits.

I purchased some new ones 10 years or so ago and the chrome was bubbled an a few, so examine thoroughly if you get this type.
The supplier did replace them.  (Sportscar Spares, Sydney, NSW - a good supplier of parts.)

Stainless sounds a good idea, as long as the correct stainless (Hard enough) is used and the manufacturing is to a good standard.  No experience with these.

[byakk0]

my original were chrome plated. Budget is tight right now, and I would like to do it correct from the start, but it may not be feasible right now, so that is why I am wondering. I can always rebuild em again later, but then I'll have to bleed the system again too...
As you can see, only 1 is re-usable as it has no pitting.

[RedRooster]

Just buy new ones, they are not that expensive.
RR