Most people run Schumacher tires on turf, but JConcepts and Pro-Line also have turf specific tires. I've never actually raced on turf, but from what I can tell, a good starting tire would be Schumacher Cut Stagger fronts with either Schumacher Mini Pin or Mini Dart rears, both in yellow compound. You can buy them pre-mounted or mount them yourself. Just a heads up that the fronts use narrower wheels than normal 2wd fronts and don't actually use inserts.