I did not know this mod before, but I just surfed a little to find some info about it. I must say this sounds A LOT like NS. Damn, I thought they had invented it all by themselfs in NS...
Anyways, Gloom sounds really cool so if you can make a mod like then then I think you got a pretty good mod. There are however a lot of other guys who are doing the same for Source. The NS team of course does it, but so do many others.
I think that you have a very good chance if you make it a mod for FarCry or UT2k4. Doom3 probably got too many marines vs. aliens already.