I'll try to release a script that starts/stops shairport on N810 via terminal and will test N900 too. If it works ok and there's interest, I could probably create a simple gui app for both of them.

770 lacks ipv6 support, but if I manage to flash the kernel and its libs aren't too old (and cpu/wlan can handle the load), maybe it's a possibility too.

EDIT: Managed to build it for 770, but it segfaults on "Floating point error" and debugging didn't get me anywhere