You should have fun with the Sonic. I don't know what the section is. It's probably one of Pat's own refinements. I know he changed the foil a few years ago to make it match the balsa TE better, but it still flys great. I've built 4 of them, and the new ones fly great too.

Play with the CG and get it as far back as you dare (as you would trim any glider) so it still tracks well, but needs just a hint of down elevator inverted. Then you can do inverted stall turns.

BTW, Pat Bowman also invented the EPP plane, in case you didn't know. I forgot to mention that before. He gives a good interview on "Lift Ticket" where he discusses his first design.