Cisco Aironet WAP
I'm very new to pfSense, in fact, I'm still trying to decide on what hardware I need/want. I've come across a Cisco Aironet 1041 WAP (seen here: http://www.amazon.co.uk/Cisco-Aironet-Standalone-Access-Point/dp/B004OXM6W4/ref=sr_1_1?ie=UTF8&qid=1325211288&sr=8-1) but I'm just wanting to know if this will be OK to use with pfSense as a WAP, or do I have to have an internal PCI card to set up WiFi?
The Cisco is a "wired" WAP. Support in pfSense isn't really necessary it will work.
You haven't said how you want it to work in with the rest of your network but there are at least two easy ways you could set it up:
connect it in to your LAN
plug it into a separate (opt) interface
That seems like a lot of money for a WAP. You should shop around a bit. These days you could probably get a dual-band (2.4 & 5GHz) wireless router for much less and just disable the routing.