My cousin bought them on the web somewhere, so I can’t help with that. They are very similar to these:
http://www.back2base-ix.com/index.php?_a=viewProd&productId=67&review=write
His were pretty cheap, but I think 8 for $12 is a pretty cheap since they have magnets in the tips.
The ones in the link have magnets in the tip, but my cousin’s didn’t. So, he bought a bag of small, rare earth magnets and glued them to the tips of his flight stands. Then, he glued small flat (really thin) magnets to the bottom of his planes. I’m not sure where he got those, but they came as a sheet, and he just cut it up. The planes sit on the flight stands really well. I’ll try to post better pictures after our next game.
Just like in the link above, his flight stands came in two heights.
He also glued a strip of the flat magnets to the tops of the carriers, and that makes a world of difference when moving carriers around.
I don’t know exactly what it is, but it all just adds a whole new element to the game.