Can't help you with the weights except to say that wheel weights from the 8N onward will work on your 2600.
As for the remote valve, my buddy has a dual remote listed for sale. If you PM me I could put you in touch with him.
Remotes for your tractor will fit all smaller fords built from 1955 through 1985 or so so you can expand your search beyond just the X600s. Expect to pay $200 for a single and $400 for a double.