Polaris VES Gold is made by a company called, "Lubricant Technologies" out of Minnesota. Its a decent oil, but its expensive.
Amsoil is pretty good, but its not the best snowmobile there is.
Personally, if you are going to spend the money for synthetic, Id go with Klotz. Its the best snowmobile oil on the market.
When you say Wisconsin, you said it all.
'01 Polaris Indy 600 XC SP EDGE XR
Powermadd articulating bar riser with 2" riser block (total rise of 4 1/2")
red Cobra low sno-x windshield
Pure Polaris handguards with Pure Polaris mounts
almond/blue drive clutch spring with 10-60 weights
121" x 15" x .91" track with 96 studs.
Citgo Sea and Snow oil