Question : WRVS4000 Router in front of Cisco ASA

Hi all
We have a customer who rents office rooms for several other companies. This customer also provides internet connection services to all these companies via a ADSL connection. A simple Linksys WRVS4000 is doing the sharing as well as basic firewall protection. One of the companies in the office is about to install there own web and mail server. They want to have their own external static ip as well as their own cisco firewalls. My customer is having a total of 8 WAN IP address and is willing to provide them with as many IPs as they need.
My question is how on earth we will be able to setup such scenario without affecting the rest of the companies who are completely independent and they just use the internet connection which is shared by the Linksys router?
I believe this scenario needs a multiwan router right? What about if i put the cisco router on the DMZ port of the linksys router?

I would really need your help here as i am a bit confused...

Thanks

Answer : WRVS4000 Router in front of Cisco ASA

In short yes.  You need more than one WAN, and one to one NAT support.  If you are looking to stay Linksys I like the RV016 and the RV082.  They have 16 and 8 wan ports respectively.  Also they support VLANs and multiple subnets.