You can get the seals. I had to rebuild mine back when the truck had about 15,000 on it (I was sick of the dealer). I do not have the part#s, but the seals were available from Dodge, and were not too expensive (there are 3 seals, each one can be purchased individually).
I have over 140,000 on the truck now, and I have not had any leaks come back on the steering box.
-Rich