I am using the MIG24WAVE since they were designed to attach to the back of a laptop and work great when attached to the back of the Webplayer. They come with the correct Lucent/Orinoco type connector that connects to the short adapter cable that came with each of my 4 Truemobile cards. The ant will not connect directly to the card, so you end up with a short cable in the middle. I have 4 running this setup and it works great.
You will need an ant, the short adapter cable will not work as an ant, even a few feet from the access point.
I org used the Orinoco external self standing ants and they also work, however you have to stand them up next to the Webplayer and they take up space. I did notice much better reception with the Orinoco ants. The MIG24WAVE ants do not work nearly as well in my location. Both are aprox the same price and it just comes down to the MIG24WAVE making for a much nicer install.
I purchased 4 Truemobil card from http://www.tlab.net/~jungmann/cables/stuff.html via eBay and each of them came with the correct adapter cable. It sounds like others were not as lucky with the cards they received.
I purchased 4 MIG24WAVE ants from this person on eBay -- http://www.stores.ebay.com/id=34898716. He seems to allways have them listed.
Here is where I purchased the Orinoco external ant I mentioned -- http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2008375055. They allways have them listed also.