Fordman1282 it sounds like you're jumping into this hobby blindly and as you said, without patience. This hobby is literally all about patience and without it, you will have a very hard time and probably lose a lot of money in the process. As others have said, its probably best if you took the clowns back and waited for the tank to finish its first cycle.
As for the Tang IMO, you will be ok getting one young and small... but in a few years you will need to take him out of the tank and either trade him in at an LFS or maybe by then you will have a bigger tank he can go into lol.
Also FYI anemones have been mention in this thread a few times so if you're considering one many anemones need very strong light to survive (maybe close to the same amount of light a clam needs) and also have a super low survival rate in tanks under a year old.
I'd hate to see you spend hundreds or even thousands of dollars only to have your animals survive for only a few months.
Oh and don't take one store's word as law. Go to several places with questions. There are some stores out there that will tell you anything you want to hear if it means a sale... doesn't matter if the advise is false or if it could lead to whatever creature it is that you want to buy to its death... a sale is a sale to some people.
As a matter of fact... go to a store and tell them you just finished cycling your tank and want to add some starfish. If they tell you don't do it yet, its probably a good store with honest salespeople.