I'd try the WR250R thread here in Thumpers, since everyone there has experience with this bike. Also the WR250 forum
I have MT-21 front on mine and like it a lot.
I have a new T-63 ready to mount when Spring comes.
I didn't like D606s on a DR350 on the road, OK off-road, and haven't tried one since. Lots of folks like the rear but not the front. Some like both.