standard linksys routers are not designed to manage more than 1 IP from a wan line. i have a 200.00 linksys rv042 that cant even do that.
your static IP's are assigned from your ISP, if you use PPPoe i assume you use DSL. I have never had more than 1 static with a dsl provider but i do with cable. this is how i think it should go off the top of my head.
linksys should be setup as a pass through authen only, in other words it should not route. the out port should go into a server of some type, or a normal comp i suppose if you want to address these IP's on a single box. In windows to add more than 1 IP you need to go into your lan adapter and tcp/ip settings, then advanced, second tab, and enter the ip's under the IP address box at the top. this requires DHCP to be off.
I have only used a server to handle this while hosing game/file servers. if you want to have your IP's assignable to multiple comps then you should be able to plug them into a switch and to the linksys router then manually set the IP's on teh systems to one of your static IP's. the comps should register with the DHCP at your ISP.
I use a cisco 1800 series box to assign multiple IP's for more than 1 network in a building. this box is designed to handle such tasks. it lets you set firewalls, IP's to various subnets and network equipment and sounds like this is what you want.