Heads up is a great style. Intense, action packed (unless you come up against mr AA/KK/QQ...and nothing else!) and if your any good, very profitable.
Just take into account the rake though. Typically 10%-ish of the buy in. So if you play 10 HU matches and win 5, your losing out...you need to be winning 6 to break even, 7 to grind a profit.
If your winning 70% of your HU games, keep at it!!!
Playing the micro stakes wont do any harm. I play tons of HU omaha at $2, and do ok at it. The heads up games are pretty soft up to the $10level imo, where the competition kicks in.
If your above average at NLHE then try the 4 seat $6 token games on Tilt, fairly easy to crack and a $26 token for winning 2 matches is pretty nice!