Internet sharing and security

[Piers Kittel <edinfo-list@biased.org>]

Hi all

Currently, I've got the following hardware:

1) Email/ftp/dns/proxy/web/dhcp/irc server
2) Linksys 3 in 1 hardware router/Wireless AP/switch
3) 2 laptops with WLAN cards
4) Spare PC
5) Spare 486
6) Rest of the network

So I've got 3 options to share out my Internet access to my internal 
network...

1) Linksys router
2) Use Smoothwall on spare PC
3) Make a custom built internet sharing and firewall machine on spare PC

Which one would be best to use?  Keeping in mind its difficult to 
control the wireless access using the Linksys.  I'm thinking it might be 
better to get a spare PC, set up Smoothwall or set up a custom firewall, 
plug the ADSL line into that, plug the firewall into the network, set up 
the email/ftp/etc server on another PC, and dig out the 486, use that as 
a bridge between the wireless network and the wired one, and use a VPN 
tunnel for the laptop?  Or should I not worry too much and just slap the 
ADSL modem into the Linksys, setup the email/ftp/etc server, forward the 
relevant ports to that server, and hope nobody hacks into the wired and 
wireless network?

Should I keep the firewall PC seperate that to the email/ftp/etc server 
or is it alright to combine the two?

Is there any benefit in making a custom firewall machine, or should 
Smoothwall be sufficent?

Also keep in mind, the internal network will be used just for me ;)

Sorry if I'm not being very clear here...

Cheers - Piers