The performance hit for 128 Bit WEP (actually 104 Bit) is not statistically different than 64 bit (40 Bit encrpytion, 24 bit cypher) That is really a non issue but if all your hardware supports WPA then it's really a non issue because you wouldn't use WEP anyway. WEP is crackable in a few minutes with the right tools.
WPA, and specifically WPA2, is pretty strong encryption. Still vulnerable to a dictionary attack but just assign a long alphanumeric password (with a capital letter or two) and you'll be fine. Radius is overkill for a home network but if you wanted the strongest possible security on your WLAN nodes then RADIUS would further lock down the wireless network. You could also run a VPN to authenticate your wireless clients. That's what I do. IPCOP firewall with it's own network segment for the wireless clients and VPN authentication to allow traffic on that segment.
WEP is crackable in a few minutes with the right tools.
What??? 128bit is crackable in "a few minutes"? Can you provide link about that? (not how to do it, but that it is possible to do)
I thought that WEP and WPA uses very similar inscription algorithm, and the difference is only in the way how you generate the key. But if the key is of the same length, I thought that it is not easy to crack either of them.