Close to the final question - manifold block (LP)

Two issues here that I've dealt with for years:

(1): You can make your own custom hoses with ease using 3/8 hose tat is vailable from McMaster-Carr, using ear-clamps also available from the same source crimped with a tool that is also sold there. I cut the ferrules off the ends of stock hoses and re-use the end fittings. Have been doing it for years. The hose is availlable in any color so blue = diluent and green = o2 on all of my rigs. I can get catalog numbers when I get home.

(2): I make (and will be pleased to make to spec) LP manifolds with any orientation and your choice of 3/8-24UNF (standard LP hose connection) or 1/8 NPT (also valuable, as you can make the above mentioned hoses with 1/8 NPT male ends easially using yet another little part from McMaster-Carr). I purchased the correct reamer to make the O-Ring port in the LP hose connection the perfect SAE specification. I use Brass if asked, but usually work in Delrin. It's fine for LP and is non corrosive. I also add things like ball shut-off valves on manifolds, quick-connects, etc. You can make all this stuff yourself but the issue is sourcing and then buying the correct reamer to port the hole for the O-Ring.