Instalation, specify network port to use for install

I have an DELL T410 32g memory single XEON 4x +4 with hyperthreading it has 2 1 GB on board NIC's I also have a fibre chanel card for the internal LAN to a GBIC module in the switch there is also a twin port NIC installed. twin SAS 300g in raid 1 mirror array

I was hoping to use port 1 for the ADSL conection
port 2 will go to the VIOP phone system

Fibre card is for the internal LAN which included a 4TB NAS

card port 1 & 2 would be assigned to VM,s installed I'm looking at this optionas I cannot see how clearvm can do virtual switches where I could use a different IP range and subnet to keep these machines seperated from the LAN other than login management functions etc.

I would have a total of 3 VM's 1. Gateway server and DHCP server for the LAN VM's 2 & 3 would be development and deployment server for my hosted website server (I dont have bandwith etc to host here)

machine config gateway 4 cores 16 g 100g disk space the other 2 machine's would be 2 cores 8 g 100g disk space