By far the easiest (or at least most available) way is to get them from reverse engineering black hole gear. You can get 50 black hole comms in less than a week now, and each pair of boots/gloves will net you 3 or 4 stabilizers if you have the right crew skills. Plus a decent chance to learn schematics and make money off those as well.
I tried the fleet comms route too originally, but after getting 1 Matrix in a box, I just stopped doing that. Worthless item from a week of grinding space missions - no thanks!
(My first box had 3 stabilizers in it, so I thought it was a pretty good way to do it, but 4 boxes later I haven't gotten that lucky again)