Well I figured out an quick and simply way to accomplish what I was after and got it done in two afternoons. Here is Bob II.
The RF20 is literally bolted in place. This makes for an extremely durable joint and still allows me to take the joined gun apart.
The original RF20 trigger has been replaced with a normal push-button valve that I mounted in the Big Blast Trigger well so I can now control both triggers with my right index finger.
Today I replaced the RF20 barrels with Polyester and gained roughly 10 feet in range.
The RF20 gets hooked up to an external tank. The Big Blast doesn't need to be and only requires 5 pumps to reach beyond 100 feet. The RF20 is the integrated primary and now gets 50-60 feet @ 50psi. The forward grip is a thin sheet of Styrene. A very easy to form plastic that you can cut to shape using scissors and can be warped and bent with only mild heating from a Hair Dryer.
Info on external air tank: http://nerfhaven.com...?showtopic=8234
Edited by CaptainSlug, 04 March 2010 - 10:27 PM.