Sealed Power pistons
The pistons in the kit are stock replacement types so if you are looking to build a performance engine they are not a good choice.
I would go to Mancini to get the kit. The prices are comparable and you can substitute parts. I purchased a complete kit for my 360 build and substituted KB pistons. As I recall it was like $60 addtional which was less than the difference between the individual prices for the two pistons.