I am wanting to add an separate antenna on a tower to my base station.  The JD manual lists off a 7db high gain antenna, but they want $1500 for it.  I have found a couple of other antennas online, the first is a 450-470Mhz 3dbi antenna (my frequency is 463.75) $150.  The second is a 430-470 Mhz 7dbi with what appears to be similar specs to the JD version but costs $513.

The 3dBi one would give me approximately the same output watts as the 2dBi whip antenna I am currently using.

Edit:  Will one of these options work for me?  My local JD and UHF radio people are not much help with this.