Which router for load balancing

We have a customer looking to use us as a backup incase their T1 goes down. I know that dlink makes a load balancing router but what does everyone else use? Is there a high-end Cisco equipment that can do that same thing?

the Dlink did not work out - it would not fail over.

Used a Linksys RV042 and it worked great.

we use Peplink balance 30 routers for such scenarios. They have 3 wan ports and do load balancing and fail over.

Jerry, if you dont mind me asking, whats the average price for the linksys rv042?