sonic, i'm looking to go with one or two vertex 1.5l reactors. The inlet/outlet are both 1/2" so i would probably do a a 45 down to clear that rear upright, a 90 to the right then when it comes time for the individual reactor outlets, i don't really know if i'll have enough room to do (2)45 elbows to get the piping up the reactor inlet or if i'll have to use (2)90s. That's difficult to determine for me without the reactor here to work with. I plan on using gate valves for 2 reasons...one, because they're shorter and take up less lateral pipe space and because they're good for fine tuning flow. I guess i'll just have to bite the bullet and get one and then just pipe it to make it work. I'm terrible with theoretical stuff...i work much better hands on.
I used a 90 with a 1/2" threaded connector attached to add on my manifold.. Bought the 90 at home depot... I dont know if this helps or not