If you have had positive experiences with both OS and TT in the past, then just pick the one you want to buy next depending on how much you want to spend this time. I doubt your new experience will be much different than any prior ones. It looks like there are several here that will take that SuperTigre off your hands at a discount to cut your losses as well. Good luck with whatever direction you go.

P.S. If you decide to pursue a four stroke at some point, I recommend not asking about Saito versus YS versus OS either