steven, I would suggest regular NIC card if you have a access. Go for wireless if its physically not possible to get to a RJ 45 socket.
As far as selecting gold or silver choose the one that's cheaper. and as Mighty John says WEP isn't secure. so it really doesn't matter if you use 64 or 128bit. also ULL should support WEP I am pretty sure LSU doesn't. karthik
