Your objective is not entirely clear, but the best source I've found for oddball and strange antennas of all kinds is Tessco Electronics in Baltimore. The variety and total number of antennas in their catalog is mind boggling.
He means for a control base setup I think. I too would recommend tessco ...

I am trying to find a "bag phone" style antenna to use on a P25 mobile radio. We are converting from an 800Mhz system to a 700Mhz system and will need to swap out some antennas. Not sure if there are any out there. Does anybody know where I can find some or can give me some recommendations as to ...