I (personally) like the 1 ton TRE's. They have 7/8-18 threads, are greasable, and come with a nice pretty little boot. You'll need a taper tool to work your pitman arm and knuckles to get them to fit, but they work great. They are typically $30 or so at a local parts store and nearly everyone will carry one. Typical part numbers are:
ES2234R (right hand thread used at the knuckle)
ES2010L (left hand thread used at the knuckle)
ES2027L (left hand threaded, high misalignment typically found at the pitman arm end).
So........I feel for your application that TRE's (1 ton) would be a best choice.