I have two reg that would work great for secondary regs in a keezer build. I actually have four of these and plan on keeping 2 of them for my own build. They are 150 PSI max input and 2-25 PSI adjustable outpu. There is one in and three out. The manufacturer is bellofram, one is a type 10 and the other is a type 100.
They are new never used and sell from $70+. Make me an offer on them.