<app-name>-<major>.<minor>.<rev>-<build><rom>-<proc>.ipk
I don't think that'll work well, personally...
It's probably better to stick with the current standard <app-name>_<version>_arm.ipk, as the package manager on the Sharp-based ROMs like that naming convention.
Also what if something works on more than one ROM? Long IPK name in that case...
Why not just another file in the control.tar.gz? Something like "compat", and come up with a standard format to look at that file and have all the stats listed.
i.e.
Package Name: foo
Models: SL-5600 (Poodle)
ROMs: Sharp ROM (and compatible)
Processor: ARM5 (Xscale)
Package name just there to make sure it matches the control file's name. Of course it'd probably have more data than just that, but hey, it's just an example.