RE: WIFI card with external antenna
I have one of those, I bought it years ago, from Broadband express, together with a little antenna that it connects to (They may still have them, check their website). Then I bought a new laptop, and I couldn't tell the diff in speed. with the anetta and card connected, from the computer's internal antenna.
Then I bought a newer laptop, and don't use it even for a lark, as it is so slow.
Like Chuck says, pretty old technology. Not worth the effort. You will likely be getting a newer laptop in any event.