a Top Flite giant scale kit has a good walk thru for building a first warbird but if you have building experience then I would suggest the Ziroli line of planes. Not much for building instructions but easy to figure out. As far as the retracts go just watch what brand you get. We use Barton Retracts and grass is not a problem for them. The Stuka is a nice plane but by the time you build or buy the wire frame and that expensive cowl and wheel pants your not saving much. You do realize the words competition level and saving costs don't fit well together Yes most of the retracts have scale oleo struts but if you don't want trouble I would avoid the rotating retracts as they are a little more troublesome than the straights. P-40 and F-4u both use rotating retracts.