You get corpses from your first mission to render no problem. If you know how to get a faceless corpse thats your elerium. you can also render an elerium core after hybrid materials which helps.

You'll be stuck on rifles for a good while though, but Shotties are pretty good earlygame, Snipers too, and Gunners get Hail of Bullets so you know they have guaranteed damage when you need it.

Once you get your Rangers up though, they become your powerhouses. I have a ranger who constantly hits 40% shots. so much so that I'm surprised when he misses. Also got an assault that hits for 32+ And thats just with the coil shotty, plasma will hit even harder... xD

Oh, and uh.. I caught up with Adventure time. And man, they are trying to end it huh?