Jeremy,
Why the two different size motors? I assume its just what you had laying around(I wish) but being brand new... and of similar displacement why not 2 of the same ?
I had some hair brained Ideas of doing a similar build a while back and chose the inline design because I have a .40 and a .15 and that obviously would not work side by side. It all started getting very complicated and I bailed - You are doing a better job than I could have ever imagined ! Stellar Work.
Dave