I don't know how they fit with Deavers, but I really like these:
http://www.sulastic.com/sulastic
They primarily isolate harshness, however they do not make the ride "plush" (but that's what you have Deavers for anyways
).
I've had mine on for a while now. I think close to 200,000 miles. The rubber torsion isolator is finally sagging enough I'll probably update them with a new set soon, since they hit the stops when loaded heavy which makes them ride like a regular shackle. They are definitely robust.