Check this thread: http://www.blasterforum.com/suspension-14/cheap-shocks-4054/
Also being in Mi, getting ahold of some sled shocks should be easy. There's lots of Arctic Cat Fox shocks that are right length, with mid 90's 440 sno pro probly being best choice. I forget now wether it's polaris or skidoo that has some fox shocks the right length.
If anyone wants or needs a linc to where I got this info from an off road suspension specialist, I can do that.