Yep. Thanks. I called A/S and they were great. Not only did they confirm 22.5 degree down angle, but felt the upgrade to 3500 pound axles would be fine. I also called Dexter and they confirmed they can make the 22.5 degree axles AND that I should also request they add the "shock kit", which they still offer. "It'll make a huge difference to your A/S". I talked to a guy in the Warranty and Service dept, FWIW.
All in all, I now feel really good about the new rolling chassis. The manufacture was going to build it with a zero degree torsion set up and no shocks.
Didn't cost me much more, and now it should, as long as all goes as planned, it should tow like a dream!