Quite the undertaking Adam,
Welcome to the world of marine fish keeping! It is one of the most frustrating and rewarding habits I have ever had
Best advice is to start with a full setup from a tank shut down. If you don't know exactly what you need you'll end up with something not quite right for your system. Shut downs in the larger sizes happen quite often but be prepared to pay for the privilege.
If you are very specific in the size of tank you want you may want to consider getting one built. When I first built my tank, (I'm on my second now) I found my inbox flooded with stuff I didn't need because I had no idea what I wanted.
For my second tank I bought a near complete setup for cheap (relatively speaking) That had almost everything I needed to get off the ground just add rock and fish.
I spent about 2k setting up this tank used, If I had paid anywhere near retail the cost would be closer to 5k. (I needed a break from reptiles too! this was the next logical step)
On a side note Lyndsy had a big tank for sale a few months ago, I'm not sure if she still has it tho she's Flash on the forum you know her as Bean.
There are many members here happy to help.