I would try Rig-Rite for the spreaders. They seem to have a great variety of this type of hardware. Rig-Rite Inc. - Masts, Booms, Spars, Rigging, and Hardware for Sailboats.
I'll try to take some pics of my set up, but there's really nothing that exceptional about the Bristol 22's rigging setup. The only challenge I have run into is leading the halyards back to the cockpit using blocks mounted to the cabin trunk, due the relatively narrow clearances between the hand rails on the cabin trunk and the companionway hatch. The bolts for the halyard lead blocks leading away from the mast fall very close to the bulkhead inside the cabin. If your mast is not set at the moment, it may be better to get a mast plate and attach blocks directly to it.