how about some infinity-minis? They are often way to sci-fi-like for Your objective (if I got Your aiming right), but some are quite "old-school-un-scifi-ish", e.g. the Ariadne faction.
Also for some special forces, some might just fit in. Worth a look, imho. And far better than abandoning the project due to not wanting GWs ^^
@ Grymn
have seen these, too, also in real-life on a table. Excellent minis! And with a bit of converting I guess, everything is possibly with these!
best wishes
DK