I just looked up the dimensions on 65g hex tanks, seems like they are all 24" tall and 36" wide so you would be able to get by with a T5 HO
fixture which would eliminate the need of a chiller, they are cheaper to run, and they are usually cheaper than most halide setups. Try the Current USA Nova Extreme Pro 6x39w T5 HO
fixture. It should allow you to keep almost anything you want. SPS
coral would need to be placed in the upper regions of the tank though.
Just double check the dimensions on your tank to make sure that it is definately 36" wide and 24" tall. If they match up, you are good to go.
36" 6x39W Nova Extreme PRO T5HO 3x10k/3x460nm Actinics by Current USA*(1080) - AquaCave