Wireless router?

[Nerius Landys]

I have a PC with FreeBSD set up as a router (NAT). The PC has several
network cards and I'm grouping the internal-facing network cards as a
bridge (promiscuous mode for the interfaces).  Everything works well.

Now I'd like to extend my wired network to include wireless.  I really
have no experience with wireless networks.  I have a couple of
computers that are wireless-ready (a laptop and a Playstation 3 that I
won in a raffle).  Is it possible to somehow add some hardware to my
FreeBSD router PC to make it into a wireless router?  What kind of
hardware would I install?  What is it called?  The PC only has PCI
slots, can you recommend a brand and model of "wireless server
equiptment" if such a thing exists?  Would a normal wireless card
suffice?  What model should I get?  I would prefer to set up static
internal IPs for my wireless network at home, would this be possible?
Or is DHCP the way to go (I hesitate at the thought of configuring a
DHCP server).

Another way to go is to hook up a standalone wireless router appliance
to my FreeBSD machine's network interface (one of the interfaces).  I
already have such a device, I think it's made by Linksys.  But then, I
would be NAT'ing both through the FreeBSD machine and through the
wireless router.  So it would be a double-NAT so to speak.  Is there
anything wrong with that approach?

So in a nutshell, I have a wired FreeBSD router with multiple ethernet
jacks at home, and I want to extend it to include wireless network.
Any suggestions would be appreciated.  Thanks.