$1.99 from Harbor Freight online: http://www.harborfreight.com/cpi/ctaf/D ... mber=93979 Just purchase two 1/4" shut-off valves with integrated check valve from just about anyone online. You can even connect two of these babies with a 1/4" x close nipple and have a 4 valve manifold. You can configure the manifolds inline, or at 90 degrees. I bought some of these but haven't got around to making mine yet.
"Reality is an illusion caused by a lack of good beer."
Interesting idea, but I think Redtail is looking to supply more than two kegs in his kegerator. Most of the parts he will need are available at any good plumbing supply. Personally I'd go with flare connectors and use check valves downstream of the individual shutoff valves. everything else though should be easily obtained locally.