That's a cool project, I've done something similar with a small frame:
I used a bull barrel comp, but I think your slide should be able to mate up to a cone comp setup like a ThunderComp 2:
The standard, large frame barrel has an OD of 15mm (.591), which could be turned down ans threaded to 0.575x40 for the TC2...
Otherwise, I don't see why the Gold Team upper wouldn't work on your frame, if I'm not mistaken, the slide is identical to the one you have on it now (except for the cuts); did one of the girls at EAA tell you that?