Try riding one, a 250 feels good to me and I'm 6ft 220. But a 450 or 500 would feel even better. A 125 is easier to handle but the 250 has a lot more power.
Look up the Ocala national forest, it is about an hour and a half away and lots of sandy trails. Never been but heard good things about it. Only thing is you need spark arrestor and muffler. I'm not sure how strict they are on noise levels.
The banshee burns about twice as much gas as the 4 strokes. The more you do to it the more gas you will burn, it was a huge difference after I put on the toomeys it burned even more.
Stand on your footpegs and rock the shee side to side, I mean bring the tires off the ground when you do it. It atomises the fuel and will crank on first or second kick.