If you can recoil a protank head, you can set up a Silica type RBA. I'm not a big geniuses (RSST) fan, mostly because I can never get a build I'm satisfied with. Bottom coil type RBAs (Term C, Ithaka, Oddy, Penny, Kayfun, etc) are very easy to rebuild. I think the Kayfun is probably the easiest...