If you're set on the mystic adept rigger, I'd definitely suggest you look at the Way qualities from Way of the Adept, which will reduce the cost of one or two of your more expensive adept powers. Plus if you get a spell sustaining foci or two, you can keep the handy combat spells sustained without incurring hideous penalties to your already quite diminished dice pool. Also figure out if you're intending on using full VR to jump into drones or just going to concentrate on remote control or even having a slew of autonomous drones. If you pick one aspect to go after you can diminish the cost. (Going down the remote control route leaves you only needing a strong command program, a decent gunnery skill and some of the other base skills that you be picking up anyway, then you can focus your mystical adept powers towards being a more capable spellcaster or summoner. Plus you won't suffer any feedback!)
Edit: Could be a nice combination if you go down the road of RC and summoning, you could summon a few spirits and send them off on their tasks, then RC into your drone while sending the others off on autonomous programs. You'd need decent a decent summoning skill and decent agent, command and pilot programs but it should easily be affordable.