You don't need overkill, like the first antenna you have linked to. The second link is probably ok but still overkill for an Airband application. Google for Airband antennas or aerials and there are many. Look for the style of the one in the second link but for airband only. Do not pay extra for one with Transmit capability as you don't need it. It needs to be a vertical rod with a ground plane that is all. Anything (largely) will be better than the antenna that comes with the scanner, those 'rudder duck' things are a real compromise. The real trick is to get it outside and as high as you possibly can.