Peter,
A simpler solution which would require less space, power, money, wire pairs, and administration for your group:
1) Provision a few Channelized DS3s into your LEC network
2) Install Channelized DS3 into your router
3) Let the LEC be responsible for owning/managing the DACS, and provisioning the FT1s/T1s onto the T1s within the channelized DS3s.
You'll save the space and power normally required for banks of T1 CSUs and the DACS, and you won't need to manage the crossconnects for the DACS.
Circuit-wise, it should cost you less to provision your T1s into your facility via a few DS3s rather than fifty T1s, and you won't eat up your incoming telco wire facilities quickly.