"So, how shall a non-FPS player get enough mats for at least 2 suits (Artemis, Maverick) in a reasonable time?"
If you're not into the pew-pew game, why exactly do you need to G5 all three suits and weapons?
I've picked up G3s from the vendors for my explorer build. That's probably enough. I mean, what do I actually need? Night vision, extra time out of my batteries, that's about it really. If I stumble across NPCs/another player I'm going to run, much like I do in my ship.
Much the same with the Maverick. Night vision, quiet footstep and being able to scan at a greater distance are all I really need to sneak around bases.
As for reasonable time? That's very subjective, but I don't expect to be running around in G5 everything within a week. - Although I'm sure there are people who already are.