It'd probably make a fine utility quad. I'd do some searching to find what you want. Always keep in mind what they weigh. It's nothing to find a 700lb heifer ATV these days. Back in the day when Suzuki still had the King Quad it was the heaviest at around 500lbs.
The last fast Polaris was the Scrambler 400. Before that, it was the Sport 400L. The newer ones are heavier and slower. They kind of sold out and started making the same stuff everyone else does. They used to say only people 18 years and older are to ride their ATVs.
I believe 4 strokes are for lawnmowers and roto-tillers. Two-strokes belong in ATVs and dirt bikes.
But, I'm about four years obsolete. I quit paying attention to ATVs when I went to college.
I have a friend with the polaris scrambler 500 and that thing is pretty impressive. It kept up with us in a foot of snow with no problem. It also pulled my snowmobile out of a snow drift twice.
On the whole keeping 4 strokes on lawnmowers thing...i disagree. I kinda felt the same way. Then i rode a 1999 XR400 and that was just unreal. I could ride a wheelie all the way through 5th gear. The only thing it took a while to get used to was the powerband. I actually was riding it last night on some trails. It does great hillclimbing or whatnot and had more than enough power to go anywhere I pleased. Thats just my opinion, but i would say go for it. BTW, the polaris that pulled me out also has a winch on there and has saved him a few times in mud and snow.