Nori sheets are the best for tangs - they are like cows and graze all day.
http://www.bigalsonline.com/BigAlsUS...algae100sheets or any asian market. It may take them a few days to learn to eat from lettuce clip, but after that, they will learn.
After that, frozen mysis, brine are good. Pellets and flake also. Mine all eat like pigs and eat anything that I add to tank. Put them in all at same time.
UV, I ran a 125 for 5 years without and added one to my new 215 system. I think it helps, keeps water clear. Opinions on it are just like sand bed or bare bottom and all the other debate ones. Everyone has opinion. Interest thing, most people who say negative things, or that they are not worth it, probably have never used them and are going on what they hear from others or read on RC from others who never use them.
Let tank run and cycle for 4+ months before you add the fish and learn how to care for your system. Add a reliable top-off system, this will keep salinity constant and reduce stress.
Another good thing to do is to add 2-3 skunk cleaner shrimp - they will clean your fish.
Try to find in the 2-3 inch size range if you can. As mentioned by others, PT and sailfin are same body shape, could fight
Finally, run a quality skimmer to export all the seaweed and food you add to system and do weekly 10% water changes or more.
Good luck.