yes the headache rack is a perfect ground and i would perfer not to mount 2 anttenas by eachother because they have to be a certine distance apart because the will interfer with eachother and to be honest on antennas i wouldnt get a fiberglass anntenna because they just rip you off you pay more than there worth but everyone has diffrent opinoins on antennas diffrent brands make there own special things but i would perfer wilson hustler preditor fat daddy oor monkey made or if you want you dont have to spend much money and its a great deal for what you get there actually pretty good go to radio shack and ask the people at the desk for 102 inch stanless steel cb whip its one of the best i personaly think they keep them in the back so you have to ask for it and there only $25 also by a spring they have there for it so it wont get all bent up and eather a ball mount if your mounting it to like a tool box or somthin or get a flat mount for like mounting on the side of a tool box or somethin and coax i perfer thick coax you get at a cb shop ask for RG8213

how far apart do dual whips need to be to not interfere with each other? i have springs on my whips now but theyre mounted on my mirrors, im worried about them slamming my stacks, is there a stiff spring out there that will hold the whips pretty straight so i beat the crap out of my stacks?

Go with a single antena. I used to think duals were good, but thats not true.