I'm not sure if this should be in networking since this is more of a general network architecture and Linux question. I'm looking for some general guidance on how to setup some new devices on my network so I dont have to do this too many times before I get it right.

I have a home wireless network w/ Linksys WRT54GS router and a WRT54GS (as a client bridge) (both running DDWRT 23sp1), 3 WinXP pcs, xbox360, and ethernet printer.
I am planning on adding some more devices to accomplish the following: NAS, HTTP server, FTP server, media server (GNUMP3d), and some other minor services (bitorrent, print server, NTP, etc.). The web and ftp servers would be used mainly for sharing photos, movies, etc. with family and others (WAN), the NAS and other services would be LAN only.

My thoughts are two PCs (Jetway miniITX J7F4k, with dual integrated nics.)

1 that would be my NAS, media, print other misc servers (right now I'm thinking ebox - eBox Platform » EBOX PLATFORM)
1 Linux PC for http/ftp server, with minimal harddisk space. (unknown distribution - also Debian?)

What is the best way to setup the machines and router on the network (i.e. connections, vlans, routing. etc.) to accomplish this in a secure way such that a problem with the web/ftp server, does not cause security issues with the NAS and other devices on my LAN? (I still plan on using the WRT54GS to do the routing).

If possible I would like to keep the pictures, etc. on the NAS and not have to copy these to the web/ftp server, and I would like to be able to manage the http server from the LAN side. Is it as simple as router forwarding ports to the "external" server (eth0 - do I need a vlan just for this?) and then mounting a volume on the NAS as read only on eth1? I assume I can limit the connections to the NAS from the "external" server to be read only (i.e. setup an account on the NAS and use file permissions?).

I have a basic understanding of Linux and dont mind reading and researching but I just need an idea of the general configuration.

Thanks for any help, and suggestions.