As long as they have either a static or DHCP address they give you your are fine. You will have a problem if they require some kind of windows only script to login. I use Telocty(now direct TV) and it works great. costs $50 a month out here in CA, you should check with them to see if they will service you. You dont have to buy the modem, they provide it to you, it is very large, but just toss it in a closet with your e-smith box. I would not go with the phone company. Also check to see if they allow you to run a server. Telocity allows it and provides static ip's and they will host your dns for you free, as long as you point it at your telocity ip, that way you can use one of the cheep registrars that only charge like $8 a year.
Sage