the wings dont do too much...i think they might help to keep the boat upright if it ever tries to flip
the 550 IS the size of the motor
if you mean the 550 for the outboard motor
http://www2.towerhobbies.com/cgi-bin...?&I=LXMPN6&P=0
if you mean the stock motors...they have 380's in them...they arent good and the electrics cant handle the setup
the best thing you can do is buy the 550 (or the whole outbord andjust set it up for that) a new esc, servo, and buy a rudder/strut combo...you might also want to add a peice of 1/4" ply to the transom, the plastic is too thin there..