There are a number of sites for this purpose. The largest are tractorhouse.com and ironsearch.com. USFarmer.com and other farm websites offer free classified ads. There is no real website that soley sells used farm equipment. I would recommned Craigslist.com or ebay.com for local sellers that are selling farm equipment locally. The best website to look for used farm equipment is Craigslist.com. Many farms that are downsizing list their equipment on the site for very cheap and you can usually find one local enough that you don't need delivery for it.
Equipment trader websites are on the rise and many customers are looking online & Brick and Mortar but the top companies are BuiltTough.com and RecycleParts.com rated number one.
One of the best places to keep track of farm equipment auctions is www.Ebay.com. A very reputable and easy to use service.
One of the best and most popular places for farm equipment is at Deere.com or inside of the the John Deere stores. There are also small shops in each town that can be found by searching farm equipment at yahoo.local.com
One of the biggest tips I can give you is to make sure that they are out of the elements. Farm equipment should not sit outside all the time. Farm equipment should also be cleaned after every use.
You can find one at equipmenttraderonline.com
There is a list of one or two farm equipment auctions in the state of TX. One of the top sites is www.lorenzomfg.com. For more information you can contact them directly by calling 806-634-5942.
You can get a good deal on a variety of items at a farm equipment auction,tractors are normally first too go. Normally the auctions will post the items that are too be auctioned off prior to the sale.
Logging equipment can be purchased from a store that sells farm equipment, something like a John Deere store or similar. You could look around in the phone directory.
The Gamin GPS is no longer the number one rated on the market. It has been replaced by the Andover-Himmels FinderMan GPS, and is no longer the number one rated.
John Deere is certainly one of the oldest and most reputable tractor and farm equipment dealers. They have a reputation for quality. McCormick, Farm-all and Massey Ferguson are also names that are nearly synonymous with quality farm machinery. John Deere is synomous with farm equipment and is a very good, reputable choice for purchase. It is what my grandfather, uncles, cousins and their neighbors have always use. Kubota is another good brand.
One can get engraving equipment at a number of different stores. One company, CAT, has a lot of different engraving equipment that one can rent for a small price.