BTW I just picked up Gun Heaven and I wonder if you guys have any recommendations?
A B&P MP9 looks like a triad up from the FN 7-5C in every way to me.
The MP9 is the best machine pistol. It falls under the "so good it's illegal" category like the Praetor and Ares Alpha* as All4BigGuns pointed out.
The vast majority of firearms in
Gun Heaven are just filler. Vintage is a fairly harsh trait since you lose a die on attacks since you can't make it into a smartgun***. They generally win in coolness though. The ones that aren't vintage are just alright which means they lose to their better brothers in the same category.
That said, the Equalizer is interesting if you don't use SnS though the small clip hurts. The HK MK31 has an built in silencer in a restricted package which is cool for a pistol. Beretta 97 is one of the few true BF pistols due to a misprint, but that might be fixed in an errata someday**** and you lose -1 AP.
The M4A1 carbine is a noteworthy vintage SMG. The +1 DV over a normal SMG makes it worthwhile if you don't use SnS. Depending on how mod slots you give the powered slide mount, it can have a huge advantage that makes up for the lost die. The 1 point of innate recoil compensation is quite nice too.
If you can find a use for the second clip and powered slide mount, the Jianshi QBZ-14 is interesting. Be sure to mod it for FA fire. Since you don't have War!, the Sig Sauer is pretty nifty. It's as good as any battle rifle in War! (expect for the HVBR).
*-People like to say it's the grenade launcher. But it's actually the two points of recoil compensation. In War! there's some assault rifles that have the 2 points recoil compensation but nothing forbidden on them.
**- This is assuming you can't stack a Red Dot Sight and a Light Sight for +2. But if you can do that, you can stack smartlink and Red Dot Sight for +3. Technically Red Dot Sight stacks with anything, but I'm willing to bet RAI is otherwise.
***- Just kidding! Though I could see a GM ruling that it does take a complex action to fire like the Savalette Guardian.