Need assistance with multiple segments and vpn access

I am looking for the following assistance; if anyone can help, I thank
you in advance.

I have a client who has the following setup

1 bell router, 2 network segments
Each segment has its own MS server.
A w2k server on Seg A and a small business server 2003 on seg B.
Its setup so that client pcs on either segment can get to the internet
BUT they are prevented from seeing each other. This is on purpose
because segment A is a test environment and the the ownwer wants to
keep it isolated.
Both servers CAN see each other via a second nic in each.
This is so pc clients on BOTH segments can get to either server.
It works ok but the owner (client) can only vpn to ONE of the servers
and not both - he wants both. The is because of the port forwarding
limitation in the bell router. Can only do one segment I guess. Its
aEfficient Networks Speedstream 6300 wireless dsl gateway
I'm told the real answer to this is to go cisco router.
But it could be big $$$. Is there another cheaper way?

Thanks;
TF