For a eight lines gateway you could use a Quintum A800. It provides eight analog (to connect to single line phones)
For internet access, you will need a minimun of 128 kb. That will be the bare minimun.
The calculation is about 16 kb for active call.
If you have access to more bandwith, getting 256 kb is like having a quality insurange.
If all what you could get is services like 64 kb, you could get a couple of A400. Each one is good for four lines.
Remember: you need bandwith on both directions. Mos ISP ‘s claim that they could give a lot of bandwith of download from the net to you. The key will be the link from you to the net.
You will need the same ammount of bandwith BOTH WAYS, unless there are going to be computers connected to the same link also.
For quality reasons, having computers and voip on the same link with not much bandwith is not a good idea.
Providers: Have no idea. Be careful and do not send big checks to people with only yahoo or hotmail e-mail addresses. Insist on a land line number to the company.
Lot of crooks out there!!!!!