If it was me I don't know if I would have any trigger with a six line, sooner or later the trigger will get too big and the six line will be gone. About the only one I would even try is a niger, and that might not work.
There is a chance you could get away with a bluejaw, pinktail, sargassum, etc. with a six line. I'd be worried a little though. What size tank is it? How much lr? Bo