wireless networking

[Eric B. Richardson]

I only have two machines I want to get together on a wireless 
network. A biege G3 updated to USB/Firewire with a G4/500, 512 MB and 
an iBook Snow Dual USB/Firewire with 640 MB. I was running an 
ethernet router that allowed me to have an effective firewall and the 
two machines could network.

Now I have an Airport card and an SMC Barricade 7004VWBR. The Beige 
is hooked into the router via ethernet wire, and the iBook connects 
via the Airport card. I started Brickhouse firewall protection on my 
Beige G3, because I read somewhere that wireless router firewalls are 
not as good as wired router firewalls.

So the problem is that when I turn on the BrickHouse firewall, the 
two machines don't see each other. It is set by default to deny 
incoming connections. So the question is how do I get the best 
security, and still allow these two machines (or more later) to see 
each other. They are communicating well when it is not turned on. How 
do I get access to the other folders besides the public?

A related question is what do I do to get Airport card traffic across 
the wireless router encrypted? does it slow down the traffic 
perceptibly? How do I know it is working?