I use to use tons of minitures back in the day, before I ended up having to sell them because of space and lack of cash. Mostly had a mish-mash with tons of GW stuff. Heres a few sites and ideas for ya though. (And I know you said no 40k, but a few here can be used I think, better than space marines atleast.) Also, trying to put up stuff that doesn't need alot of converting and shit.
Necromunda:All are armed models, but good for low level runners, armed civilians, grunts and most of them are great as gangers(kinda makes sense).
-Orlocks: Make great guerillas, mercs, and the older ones (which I prefer) are good for alot of civilian and labour work characters
-Delaque: Spy/conspiracy based antagonists/contacts, smugglers who watch too many trids etc
-Van Saar: Guards, mercs, military, militias and anything that you feel would be uniformed up in bodysuits and milspec-ish gear
-Ratkins:Tribal and NAN models, tribal gangers, low end Z-zoners
-Scavvies: Glow city gangers and craptastic gang scum (rusted stilletos come to mind here), poor grunts from 3rd world countries
-Arbites: SWAT, HTRT members, High-end gov't/corp troops
-cawdor/redemption: Hard to find a spot for them, but used them for the UB back in the day. Could be used for cults and the like though.
Tau: Mostly for High end, heavily equiped milspec troops. Used the fire warriors, path finders, and stealth suited troops for High end grunts and important chars, with a few head swaps for the helmetless troops. Used the drones as well, drones (one of the easiest things to make actually, see lower down.). Also, used the kroothound as a basis for a few different paranormal animals, some had the spines clipped off though.
For any other GW stuff though, I used it on a item per item basis. Some necron stuff became drones, some tyranid and DE stuff were paranormal/mutated animals or biodrones. IG was easily troops, but were too bland.
Rezolution:While alot of the models are damn amazing, and beautifully, done, they are even better since alot of it can be used in SR. A guy happens to be floating? Hell he is probably the mage, geek him. The huge guy with the big gut and the small gun to compare it to? Well he is an ogre or with some green stuff a troll.
Grenadier models:While technically not around, they have some less than decent models out there, but hey, ya may like them....
em4minitures - Future Skirmish: Yet again, pretty damn nice models, and some better 'civilian' models to boot. Got reporters, business men, musicians and the like all mixed in. Plus only a few bucks each.
Wyrd games:Some models, not much, but some that could fit in, depending on your campaign.
Copperstone:Another good site, has some of the same stuff as grenadier did, so may have the rights to their crap now, even named future wars aswell, so more than a possibility. So far, only ones I own (and still do) are the bio-chem soldiers. Also have random bits and gear for scenery
And one of the last ones Ill put up here,
Heresy Minis, which has some nice models, but not much of it is that cheap, when compared to other places, and very little (but some) fits.
Oh and for the SR minis, here is the site that has them
Ironwind and if you need to find some more stuff,
Noble Knight has alot of OOP models on there site for sale to check out.