What margin? If you work at a prop firm, you dont have to put up any of your own capital and, if you are as good as you say you are, you can trade up to as much as you want! You will not be limited by any $$$ amounts intrad day (except when you're doing MOC's at end of each quarter). At my firm, the limits are set by your position size in terms of shares and open positions (different stocks at any given monet) - not by $$$ amounts. And my current limit is 8,000 shares, 15 positions. And Im no big fry. That's 15 x 8000 = 120,000 possible # of shares I can have open at any given moment. I have NEVER EVER maxed my limits out...but that is always a possibility.
If you're as good as you say you are...go to a prop firm, prove yourself, get your limits raised...then the sky is the limit !!