
Hold on there!
The linksys device only has four 'LAN' ports and no WAN or uplink port. It has no firmware that allows it to grab an IP address from the VM modem on one of those LAN ports. Yes, you could setup an isolated Wireless LAN but it wouldn't be able to connect to VM.
If the OP wants a wireless VM connection, why not ebay the WAG354G and put the proceeds towards a new WRT54G.