Also arm yourself with cash. Then start haunting the dealerships nearby and get to know a salesman at each place. Talk with him about what you want, explain that you will have cash for the right machine, and ask him to put you on his list of people who want a machine like that. Come back or call every once in a while -- every week or two -- and he'll know you're serious. Besides, visiting a tractor store/lot is a pretty agreeable way to spend some time. /forums/images/graemlins/grin.gif You can also learn about model names/numbers so when you see an ad somewhere you'll have a better idea what it's about.
Keep an eye on local auction listings, and also the little books like autotrader. Web sites like the JD site also have a lot of used machines, but more important, links to dealers. With a used machine, it isn't a big deal to not buy locally, but check out the reputation of the service departments of the local dealers to see who's friendliest, most helpful, best work, best price, etc. Let any bad info along this line help you narrow your field of possibilities.