If you are gonna fly off grass (which is difficult-) then I too am a firm believer in the Spring-Air retracts, because they are STOUT- You will tear the mounting blocks out before damaging these units....
Please do not get a propjet with fixed gear, kinda bad for our reputation-
How long is this grass? My Patriot/ Jett-50/ Spring-Air combo. with split flaps got off the ground quick! But If the gear were not perfectly straight on the takeoff roll the tire would spin off the wheel (on one side)--- No damage but funny seeing that thing roll into the bushes then landing on one tire and one plastic wheel-