Is This Possible Using Voice/voip Lines?

I currently have a dialup isp. We use a couple of wholesale dialup service providers to provide service to our users across the nation. I would like to provide my own dialup services across the nation if the cost is justible.

Here is what I want to do:

1. Buy a remote access server (RAS) with hundreds of modems in it. The RAS will have multiple T1/PRI/T3 interface cards in it depending on which one I get.

2.Place the RAS in a Houston, TX datacenter.

3. Get voice services from a carrier that can deliever multiple T1/PRI lines (or a T3). I would want a local DID or phone number in hundredes of locations across the nation. When a number is called, it would be rerouted back to the Houston, TX PRI/T1/T3 connections WITHOUT ANY LONG DISTANCE CHARGES.

Is this possible without paying an arm and a leg for it? Can anyone give me any recommendations besides stay with a wholesale dialup provider.