[mikeytown2]

You'd need two radios, one antenna stacked on top of each other. Z offset of a minimum height of 1m/3'. In the X,Y offset of 0,0. You want high gain 8-10db antennas in this arrangement; you'd need more space between if you use lower gain antennas.

If you're looking for parts the Diamond BC920 is the best antenna. Station G2 with a $100 3-4mhz cavity filter for each frequency as well.