There is a specialty vendor on Ilum that sells a droid core that contains a level 22 Blue tanking mod in it. There are also vendors on Voss and Taris that sell Powertech and Droid pieces of gear that have lower level tanking mods.

I've bought several of these, removed the mod, and RE'd them but so far have not learned the schematic. However, it doesn't give me an error saying that the schematic doesn't exist so I'm still going to keep testing as soon as I have the funds to do so.

Help and more research on this would be greatly appreciated.