Welcome to the forum.
A few things to help you in your search that don't turn up in the regular technical discussions: 1981 and up bikes have a bit more horsepower, a lighter clutch carrier (flywheel), and nikasil plated aluminium cylinder sleeves (very, very long lived and better heat dispersion than cast iron). Don't let the odometer scare you too much (provided it hasn't broken). These bikes are finally broken in when others of the same vintage are often laid to rest.
Aftermarket suspension in the rear is a big plus. Most people seem to dislike aftermarket springs in the front forks.
Winter is a great time to buy a bike! They get much more expensive in the spring when the demand goes up, especially when they are in turn key and go condition.