Here's the results of my Flash Gitz/Nobz frankenstein project. When the Flash Gitz box came out they were being marketed in the White Dwarf to be interchangable... so I thought I'd give it a try. The first issue is that most of the Flash Gitz bodies have a much wider stance, and don't really fit on a 25mm base. So, I only used the narrow stance Flash Gitz bodies, but used all of the Flash Gitz chests to make the Freebooter nobz.
On the Flash gitz side, the nob chests fit fine with some minor modifications. I was able to get some neat snazz gun poses that were slightly different than the normal Flash Gitz, although not really enough to break up the monotony of that kit.
I left arms off of most of the nobz to wait for the new codex to land... I don't want to build of a mob only to find out that they weren't kitted out correctly.
Nob Body, Snazz gun, Flash Gitz Bitz
Flash Gitz Body, Nob Big Choopa
Nob Body, Flash Gitz Chest, Flash Gitz head