It might be bad form to post on your own thread when no one else has, but...
I've received some Brocade 10G-SFPP-SR 57-0000075-01 10GB 10GBASE-SR SFP+ transceivers. I decided to test them out in my Aruba S3500s by using them on the stacking interface.
Happy to say they worked perfectly. Not bad for $5/ea on eBay.
(Edited)
I've also found some Finisar FTLX8571D3BCL and they are also working on the stacking ports, but only after rebooting the linecard (but not the existing stack). Not sure if that is normal process or not on these switches.