Good luck. They are out there. If you cannot find one within your budget, the 3.5 is no slouch. It has never left me wanting for anything, and it recesses for the rear movements.
There is one on the bay now But at $500.00 I think that is a high price to pay, Hang in there and you should be able to do much better and you might have to buy a
complete kit to get one but if the price is right.
I picked one up in Sept 2010 with a Super 23 body,a 6x7 back the lens and Handel For $311.00 had to get the shutter repaired and a CLA for $144.00 .
It was well worth the wait.