When I'm finished rehousing my Amiga 4000 in a big tower case I'll see if it works with my Delfina Lite.
One problem I have found using Amplifier to stream off the net with the Delfina is it doesn't support the lower Kbps rates common with dialup connections (e.g. 16,24 Kbps). Rates such as 96 Kbps seem to work fine however. I believe this to be a limitation of the delfinampeg.device rather than Amplifier. As your software will use delfinampeg.device as well, it may have the same limitations with the Delfina.
I contacted the author about this a while ago but haven't heard from him on the subject. I may end up picking through the code myself as it seems like only a minor issue.