Nicest stock sled I have ridden is one of the Rev XPs, 2008 800r MX Z Renegade. Wicked sled but on 10 degree or below days I think I would get too cold riding in my current gear as there isn't much wind protection.
http://img.alibaba.com/photo/1045768...Snowmobile.jpg
My favorite mod sled is a 2001 Edge XCSP with 170hp 800 that looked completely stock but killed everything across the lake and ran on pump gas.
If I were to buy a sled, I guess I'd look for a used Rev or if I could swing it a Rev XP based skidoo for the next couple years and then the plan is to pick up a used Rush 800.
The Polaris 700 dragon looks good too! But I also have a soft spot for the 04 polaris 800 Pro-XR.
Taconite is some good riding but can be rocky when the snow is light. I like the Vermillion area. Voyagers is my favorite MN riding but nothing beats the UP except out maybe mountain riding. We lake/river hopped all the way from Crane Lake down to Embarrass and back one day, had fun in Tower and got lost on the way back 320mile round trip.