Another free, if grindy, way to get the Stabilizers/ Synthetics is by doing the entire set of Space dailies. Doing all of them yields 100 Fleet Comms and a Grade 8 Crafting Mat costs 200 Comms. If I'm remembering this correctly, it should only take 2 days a weeks to get a chance at either of the mats. On the off chance you don get the mats you wanted you could always sell the ones you got from the box as well.

Also, I've never RE'd a PVP piece before. Is it actually a 100% drop rate for Moles to come from a WH piece?

yeah, from what I can tell, all the stuff you can RE from black hole gear based on the crew skill, you'll Guaranteed to get 1 stabilizer. I RE'd 1 wh armoring on my cybertech toon and got 2 stabilizers and a matrix once, the other 2 times, just 1 stabilizer. earpiece, 1 stabilizer, 1 matrix cube. enhancements on my artifce toon, 1 stabilizer. I imagine the relics are REable for stabilizers on artifice toons and implants on biochem toons.

I tried the space mission grind before too, grinded space for about 6 days, got 3 boxes, 1 had 1 stabilizer, the other 2 boxes had only a syntheic energy matrix, think one of the boxes may have had 2. wasn't worth grinding space for the boxes, imho, especially if you get unlucky only getting the matrix a bunch of times, then only netting maybe 20k on the gtn.