IMHO - crosshatch triggers should not be in anything less than a 200g tank. Mine was in a 180 and seemed VERY cramped.
If you are going to go with a crosshatch, try to find one that is 5-6" or less (very tough to do so).
I loved my male crosshatch, but like any fish, the larger they are when they are introduced, they are harder to keep.
I would say for your 165 go with a Sargassum. They are great triggers and seldom seen. They are also beautiful and best bang for the buck.
Good luck