Hi guys.

I'm fairly new at the voice game, and this is my first port of call.
Please correct me on any incorrect assumptions I may make (read: n00b).
Please excuse if this ends up as a repost, as I tried posting this b4, but it's gone unposted for some reason

Current scenario:
I've signed up with WorldExchange (GREAT service/speed, poor billing; story for another day) on their "torrent" pand, and got my "free" SIP account through the VFX.

I use a Linksys WAG54GP2v2 to "dial-up" & keep connection open, host my physical phone line (aka. hw-based SIP client), & act as my first firewall. DynDNS coming soon. So far, so good

Next I have a Endial firewall, that I may scrap in favour of good-ol' IPCop (ol' faithfull). Endian had a facility to act as a SIP gateway/proxy, so that's got me really exited. Squid cache, SPI, DNS, DHCP, blah, blah, blah

Next, on the 'inside' of my network I have a windoze (XP/2k) box (testing, NTFS, all the other cr4ppy stuff it's just easier having a box for), Ubuntu to manage my scheduled torrents via TorrentFlux & act as a media server (SlimServer), and optionally as a Asterisk box (?), source compilation, testing & some other stuff.
I also have a dd-wrt v24 rc6 flashed Linksys WAP54G for my WiFi. Looking ar setting up a Public WiFi in my neighborhood to resell & make some money off my killer connection (via hotspotsystem).

Other clients include my MacBook Pro, Mac G5 & Asus eeePC 701 UME (& then some)

All seems good so far

A few questions arise around my setup.

Can I set up Asterisk on my Linux box to act as a gateway & use Gizmo5 SIP VoIP client to connect through it out to my SIP account hosted by WorldExchange VFX? Would I be able to connect from outside my LAN to my Asterisk box to make international calls with my VFX account?

Am I going about this the right way?
ANy other goodies anyone could suggest for my setup?

Your 2c's worth will be valued