It appears that a micro-noc 2200 from Titan Wireless has the PCI slot and ability for T-1 functionality. My question is, what T-1 card is available? Having spoken with 2 vendors, no one seems to be able to locate one.
Well Mikrotik doesn't have a compatible hardware list so I'd suggest looking at Vyatta, it supports T1s and they have a list of tested hardware, and to top it off it's free unless you want enterprise support.