As a former product manager for a physiologic testing equipment manufacturer, I tried very hard to find digit cuffs other than hokanson cuffs, as we had so many failures, all to no avail. Medasonic is a dead end. Koven Technologies in St Louis makes a robust disposable cuff, but the PVR tracings were different when compared to same-size Hokanson latex cuffs. I noticed on their website they list 1.9 and 2.5 reusable cuffs, but I'm not sure if these are Hokanson cuffs.
Gene Hokanson had been developing a digit cuff with a non-latex bladder last year. Might be worth a call to their office to check on progress, they're nice folks.
Good luck, and if you find anything, pass it along.