Will a sum to 12 or 14 build with prime runner work well with these character builds? AI drone rigger that steals cars, aircraft, and drones, a mystic adept shifter that specialise on infiltration magic or healing+combat magic mystic adept?
I can't tell you about the AI, because I don't have that sourcebook. The shifter mystic adept, you need (my recommendations) - C or better metatype to be a shifter, A Magic, A Attributes since you want high physical
and mental stats, C or B skills to cover infiltration
and spellcasting, and E Resources (since that is 100,000 under prime runner rules, and you don't have anything too pricey to buy). A pixie mage with combat and healing magic would be the easiest to do - you can make one under
normal sum-to-ten or point build. The only roadblock is if you want him to have a decent first aid skill, since pixies start out with the Uneducated quality, which makes technical skills more expensive to buy. But if you just meant some healing spells, then he's a lot easier to make (although if you make him under sum-to-12/14, you probably will be able to afford that double-priced first aid skill).