Well, if Ebay doesn't work for you, then either you are buying used from someone you trust or new from a VAR. Eschelon is a good resource in yer area, as they are the largest Inter-Tel reseller in the world. The first step is securing yer PAL.

Second, you put in yer order for the ISDN circuit. It must be configured for NI2 or National ISDN 2.

Third, if yer gonna support yerself, you will, on the night of the cut, program yer T1 card to a T1 Primary Rate Interface Card. Change 'CO Provides Progress Tones' to 'Yes'. Change 'Central Office Switch Type' to 'National ISDN 2'. Double-click on 'Call Type' and change the International Call Types to 'Unknown'. If you can't call International, change this back to 'ISDN'. Double-click on 'Circuits' and program the circuits that you have to B-Channel. Go to yer T-1 Trunk Group. System>Devices and Feature Codes>CO Trunk Groups>T-1 Trunk Group>Trunks. Right click on the gray and add yer B-channels.

Test. Make sure you can dial local, 800, and LD in and out of state. Do a 911 test. If you do not get caller ID name & number, it is the provider, not the PBX. If you think you need more support than this, PM me and I will give you my cell #...