My best advice right now is slow down. I understand how exciting and wonderful this all is, but it requires planning and careful stock choices.
Are you going to be building a Reef tank with corals and shrimp and stuff? If so that is going to impact your fish choices a bunch.
If you are going FOWLR (Fish Only With Live Rock) you have to see which fish can be kept with what, as you will end up spending money on fish that just end up dying.
Really, this should be the first step, because down the road it's normally to late and you start spending even more money in the long run. That and like the stores around where I live do not take fish from home aquariums. You can't just bring them in and trade them. So If I had a bunch of triggers and wanted to go Reef, I would have to find some way to get rid of them. So really, figure out what you want to do with the tank first. Though I must say, I think once most people see a well thought out and stocked reef tank, they are instantly lovers, and are easily converted
.
Also, when you are calculating out inches of fish per gallon of water, keep in mind you need to use the MAX size of the fish, not the size it currently is. That alone will probably save you money (since you won't have to go out and buy new tanks to setup
).
Put the Moorish Idol out of your head. They have a horrible survival rate and should really be left in the oceans. The exception of course are the public aquariums and really experienced people who have the time, money, and equipment to dedicate to that fish. They in no way should be introduced into a typical home aquarium.
Gold Striped Clowns - If you can get a mated pair great! If you can get a m/f pair - ok (I have heard of them fighting with each other still, even being different sexes). I wouldn't suggest just going into the shop and getting 2 of them...I am sure with in a few days one would be either dead, or darn close.
Tangs - Can be tricky as they tend to be less resistant to diseases like Ich. Powder Blue's also have a very poor survival rate in the home aquarium and are not generally suggested as a good canidate. Blue Hippo's do much better, as do purples(From what I hear, I do not have one). Difference being Purples tend to be around the $150 mark, and Hippo's tend to be around $40-60. Tangs get rather large, and can be quite aggresive to their own species (much like every other saltwater fish). Careful selection is required to make sure you are not going to get 2 that will constantly be battling it out, leaving one impailed by the other's long spike near the tail.
Coral Beauty - Very pretty and not to bad to take care of. If you are planning on doing a Reef Tank (which is why I mentioned figuring out what kind of tank you want first), I would suggest leaving this fish out, as they are prone to nipping at Large Polyp Stoney Corals...as are all Angelfish. There is no "reef safe" angel, they are all either a "No" or "With caution". More often then not, you will start seeing corals disappear from angels.
Black Cap bass, Cardinals (I say this because most do better in a group of 2 or more...again research will tell you), and the Clown Gobie are all pretty good choices. They are interesting fish, and given the space they will have to roam, I think they would be just fine. For Cardinals I would look at the Kaudern's (also known as Banggai) Cardinals. I think they are probably one of the neater Cardinals, fairly easy for care, and for the most part are pretty hardy.
I hope this helped a bit, just my experience so far. Good luck and welcome to the forums!!
(if you are, hide, some of the damsel fanatics are going to kill ya 
