I have a client who's working on bringing 4 T1's into a building. The client then wants to lease the space in their building to small business and offer the Voice and Data. On the data side, I'm looking for recommendations on equipment to combine the 4 T1's into a single line of traffic and split the bandwidth across the network. I'd also need to be able to NAT the multiple IP's across the network. I've seen some equipment that will combine the 4 wan ports into a single LAN, but no option for the Nating the multiple IP clusters.