Browser based desktop support

I am looking for the best product to support a remote office over a WAN (ISDN/DSL) connection. The clients are Win2K/WinXP and would prefer a browser-based solution.

We are currently using PC Anywhere over an ISDN but this is proving inadequate.
The client should be easy to install/configure and be solid.

What are the product options today, and at what cost?

Thanks in advance,

Alan