Multiple Public IP's to route to server

Hello,
we do have the following requirement:

we need to implement a scalable solution where we can provide for each customer it's own public IP so that they can access some content restricted by IP range.
the solution consists of a proxy software that will "listen" to multiple IP's, then reroute the HTTP requests and rewrite the URL's to a different format.

Anyways, we came to the conclusion that what we need is the following:
- broadband line with a pool of 8 IP's
- a router that can support multiple IP's
- a server

Can anyone suggest what kind of router or device is required for this kind of configuration. basically the network diagram will be like this:

Internet ----> broadband -------> cable modem ------ > multiple static IP router -------> server NIC

we should be able to add the same above combination once we run out of IP's, another broadband line, another device and server ....

I think a Sonicwall TZ210 or a Cisco 1900 should work for you either one will set you back about $1000

a way cheaper solution would be to take an old computer with two NICs and use a FREE linux firewall software

our old PC running OpenBSD Firewall has a range of 13 Static IP assigned.

and yes the TZ210 should work