I honestly don't know of a good forge that is commercially available for Bladesmithing. Forging blades presents some unique needs. If you doing only straight steels, you can get by with one of the square/rectangle design forges, but they are terrible for making damascus.
Ideally, you want a forge with a round interior (like a tube), with a burner/burners that enter at a tangent to create a swirling flame pattern. Any forge that has the burners pointing directly where your workpiece will be should be avoided. If burners are pointed directly at your work it can cause all kinds of issues...especially when dealing with high carbon or alloy steels that are used for blades.
I always encourage folks to build their own forge. Plans are easy to come by, and building your own forge will give you valuable insight into how a forge works, which will only make you a better Bladesmith.