I didn't see it mentioned, so here's what I'd like to see for a build it your own; with options. Since the demise of the 547, I've wanted to see a good 9mm option for awhile, I was never crazy about the 940, but it would include options like that (J-frame).
If I could build my own optioned and ordered revolver, it would be a L-Frame, 9mm (7 round), two peice barrel (like the 619/620) heavy barrel, semi-lug, fixed sight, 4" barrel round butt, and in stainless. Finally, the old 547 cylinder system, which did not require moon clips. In the end, it would look something like this photo (my current 619)
Options could be K-frame (6 round), moon clip version cylinders, 2 1/2 to 3" barrels, adjustable sights, full lugs, etc., but what I listed first is what I would order.
At this point, I'd just be happy if they simply re-ran the 547 production line, or at least made the current model 64 with a 9mm moon clip option.