Project - PPPoE with public and private IP's and VRRP on VIA

I have begun working on a project and I have come accross some warning signs.

I have 2 CV860A VIA VT8601A & VT82C686B EDEN on board CPU (533MHz)

It has 3 NICs.

I plan on using one nic for PPPoE, one nic for public ip addresses termination and one nic for private addresses termination.

I plan to use a seperate nat (my sonicwall with av subscription service).

I need to handle up to 200 customers at about 25-40 mbit full duplex.

Should I used different servers for the concentrator?
Will I be able to get my dual route PPPoE working?