Hf
King used to make a very good one which I used on a 350 but it had a wire antenna around the side and rear of the aircraft which is not a great idea if it breaks free. You couldn't certificate that arrangememnt in the UK but that may have changed with the EASA thing. However, I've never known one of the whip type antennas that stick out in front of the aircraft be much good because tuning was always an issue.
How about a small satphone as an alternative?