If you are interested, Noble Trader will allow you to use your cash immediately after you sell the stock, i.e, trade as much as you want intra-day. $10 per trade or a penny a share, your choice, AND, they allow you to short!! Those guys are very "day trader" friendly. I have no affiliation with them other than being a happy client. In my opinion, their customer service is outstanding. Hope this helps.
Bill C.