Replying to Buying used snowmobiles?

I'm looking into buying a used sled for the upcoming winter, and know absolutley nothing aboout snowmobiles other than how to start and drive one. i mainly plan on using it to access trailheads for backcountry skiing areas that have semi-maintained snow roads, so not for deep pow sledding. budget is in the 1000-1500 range....

any insights?

what brands/models are legit and have good reputations for longevity?
what features are a must?
can most sleds handle towing 1-2 people behind on top of 2 people on the actual sled?

thanks in advance