Brian,

Look for a 1955 - 68 Chevy smallblock with no air conditioning or power steering. I think that's the last year for short waterpumps.

I built my own brackets for my A-bone. This is a big block, and the photo isn't too good, but you should get the idea. It's just a flat plate bolted to the head, some small diameter rod in front for the braces, and a through-bolt with a spacer to line up the belt. The adjustment was via a rod with clevises bolted to the other head - which unfortunately doesn't show up in this photo.

Hope this helps.