Aaaahhh, my friend- be prepared to SPEND!!! To get the level of equipment deemed "necessary" by most of us here and with the proper flow rate, water turnover, LR and LS it cost me about $4,000 to set up my 125 for the same purpose. It was about an additional $200-$250 a month to keep it going. My tank was extremely healthy at all times and the benefits were very extraordinary animals. However, you need to really consider the overall scheme of having a tank that size. First, its expensive. Second, water quality is paramount so there are alot of lonely nights spent changing water. Lastly, there is a very restricted list of animals that may be kept with sharks.
As for equipment, we will start with a wet/dry system. It needs to flow about 1000 gallons an hour minimum for proper dissolved O2 and overall turnover rate. I will also recommend using a non-u-tube overflow. These can easily be disturbed at night by the animal and stop filtration. I used a CPR dual outlet on mine with 2 MagDrive 750s (about 1400 gal/hr) for returns. Next, I recommend using a large canister filter for the purpose of running carbon. My choice was a Fluval 404. Use who you trust. Moving on, you will need a LARGE skimmer to keep up with uneaten foor, waste, etc. Go as big as you can afford and put it high in the priority list. I used about 200 lbs of LS in my 125 to make homes for my rays and about 60 lbs of LR to make a cave for the sharks. Buy big heavy pieces and be sure to use epoxy to hold them together not to crush the animal. Lastly, I would also recommend UV. I noticed a significant increase in health when I started using it on my tank. The LFS can set you up with the proper wattage and pump. Also, when you buy this stuff remember that LFSs lie!!! (except you Cincy!) Be sure to check with the experienced board members here before wasting time and money.
I always fed my animals fresh seafood from the store. It was also soaked in a multivitamin at least for 24 hrs before use. I used Kent Zoecon. Take your pick of them out there. Anything else?