Your crew skills trainer i thought had the green ones and from there you craft til you get up to purple,atleast i thought the trainers have them,if not check the GTN for the schematics.
This is false you are either thinking of armoring and mods for cybertech and enhancements for artifice or the augmentation KITS for armormech and synthweaving. Augments are crafted by armormechs, synthweavers, and armstech and the schematics are only obtained through crits on slicing missions.
I'm almost certain they drop any time you crit. If you're not critting, perhaps your companion affection is low.
Most Slicers are totally swimming in these schematics though so you should be able to snag them off the GTN for a pittance. In fact when I get them I usually just vendor them rather then sell them on the GTN because the prices are lower than what the vendor gives you.
This really depends on which level of augment you are looking for. If you are looking for the top end schematics (rank 22 for level 49) then yes most slicers are swimming in them and can be acquired for dirt on the GTM (I don't even bother trying to sell them on the GTM anymore, I just vendor them).. The lower level augment schematics are a different story. If you get them while you are leveling slicing congrats, if not, I would not farm for them; get what you can and deal with what you got.