I'm using EAPPS hosting for Seam and they have a full LAMP stack installed as well if you want to use php and apache.
It would probably be best to proxy your Jboss instance with the provided Apache using modjk.
This would allow you to mix Seam and php as well as static html.
I think my setup is easier than you/I think. The two implementations do not interleave, neither the Java code will ever try to invoke any PHP stuff, nor will PHP try to reach anything Java'ish...
I can probably go with Apache vhosts, I'll have to find an adequate source yet.