Re: lt 50?
If you decide to go with the Kasea mini 50, check out my post that I bumped up. I put 15" SnowHogs on the front and 13" SnowHogs on the rear (see pictures). I didn't think the 15's would fit on the back, but now that I have both sizes, they will easily fit the rear too. I've left the 13's on only b/c its more like a MX setup, it has more torque and acceleration, and after all the hop-ups, I don't need the extra 2-3 mph top speed the taller tires would give. But if you're going to ride in sand and trails alot, I'd suggest the 15's all the way around as you'd get more ground clearance and they won't dig into the sand as easily. One of these days I'll get an extra set of rear rims and buy another set of 15's. Then I can put whichever size on, depending on where we're riding. The stock tires suck for anything more than riding in the yard. The SnowHogs are $20 each from WalMart and fit the stock rim.
Best of luck with your choice,