I don't know about the provider part because we don't have those services here yet, but how do you have your system configured - mostly IP (HFA), mostly SIP, digital?
If I understand this right, the same STMI card(s) that handle your phones also handle your trunks in this case, so you would need to have enough SIP capacity to cover the trunks configured on the boards. If you don't have enough SIP ports configured you would either need to add boards or reconfigure boards. To reconfigure the STMI board to change the allocation of SIP vs IP requires you to delete all the stations off the board (or at the very lease change all their PENS so nothing is configured on the board.
One board can handle up to 120 ports, but I would not configure more than one PRI per board no matter how many open ports are on it from both a redundancy and traffic perspective. If you have more than one cabinet I would even try to spread them out across the cabinets.
License-wise the 4000 port licenses are good for anything so that shouldn't be an issue.
Being in healthcare I subscribe to the "christmas lights" analogy, and try to avoid a situation where if one goes out they all go out. I have 3 PRIs at the hospital - one comes in on copper and the other two on fiber, and I also keep my Cornet DS1s separate from the DS3 the IT people are using - I figure if that DS3 goes down we will lose all of our computer communication but more than likely still have the phones, and if one Cornet goes down the other 6 are still up and running - just a wee bit less stressful that way!
Hopefully there was something useful in there!
