The raydan has the upper beam built a little different than the hendrickson. We've got two on raydan and two with hendrickson air over walking beam, and the raydan's are nothing but problems, and the hendricksons have been trouble free. The two with hendrickson, aren't as heavy (10k lighter gross) than the ones on raydan. My raydan's had been worked on before I bought them, and all the used ones I look at have been worked on also. I don't know why they don't hold up, but they don't.
The hendrickson air over walking beam we have is similar to your picture, but I think the bags are slightly more rear of center, and the center pivot of the lower arm looks different.
If I was replacing a pad suspension, I'd probably just buy a cutoff rear with neway or hendrickson 4 bag, and call it a day. You can get 46- 52's in 4 bag. Our new lowboy truck is 75,000 rears with 4 bag neway. If 4 bag just doesn't have enough articulation for your use, I'd do a chalmers.
Find a cutoff with the same rears you have, and its a great spare parts source, or get rears that are a heavier, or a gear ratio you want better than what you have now. Used cutoff's are usually $2,500-4,500.
I bet that rubber pad beats you to pieces empty. I used to run around all the time with just a walking beam under my old groves, but they were never empty. We put a air tag on the rear of one, and that tamed the bouncing a little.