Since i really wanted to keep that gasket that came with the cooler and instead of making a bulkhead and using o-rings on both sides and what have you. Plus i wanted to use 1/2 cpvc for my manifold instead of a supply line, so heres what i built...
Parts of importance from left to right:
1/2"cpvc
cpvc 1/2" adapter

1/2" fip x 3/8" reducer

3/8" x 1 1/2 nipple
the magic cooler oring/gasket
3/8 copper nickel plated ball valve
and so on and so forth.
PS...Menards sells 5/8 stainless steel washers for .59 cents per
Now for the pics, i just cut a piece of cpvc to demenstrate, (ya will have to put a coupling onto that to make the manifold) still have to construct the manifold yet..
Hope you find this useful and will be able to use this idea, i havent seen anything like it on here and i did some searching for a loooooooooong time...