I just searched for one that was the best bargain. aka finding one that was close to my area with low mileage, and wasn't too pricey. Luckily there was one relatively close to me with fairly low mileage and was dirt cheap. It runs great. Whenever you find one that looks good just call up that junkyard and have them check it out for you.
The only problem with this website is that it doesn't list every junkyard out there. Only the ones that have registered to that site. I would also look up some local junkyards in your area and see if they have one. "U-pull-it" yards generally have lower prices than typical junkyards. Only catch is like the name says, you have to pull the part yourself.