Differences in Autocockerparts.com valve kits?

[spartan985]

Pretty much what the title says, can MCB enlighten me? Low pressure VS Stainless VS Gold VS Brass? Opinions on what's the best kit to buy for a RF project I want to start over the winter.

[jetenginekyle]

low pressure = shocktech clone but with a wgp hammer
brass and stainless = wgp clone
gold = ccm clone, and a very good one at that
ics = karivorr clone

[jetenginekyle]

"Opinions on what's the best kit to buy for a RF project"

Type of build and goal of the project?