Is there any broker that allows me to reinvest money from a short sale?

From what I understand, when I short-sell a stock, the sale amount gets credited to my cash balance, and often have to pay a 0% interest for the position (depending on the broker and how hard the stock is to locate). I also know that because of regulation T, I need to have 150% of the value of the shorted stock in my account (100% of the current market value and 50% more as collateral). I am wondering if there is any broker that will allow me to keep that collateral in the form of stocks, but more importantly, if there are any that won't charge me interest when if I do so? (many don't charge interest for just borrowing the stock, only when I try to reinvest the sale proceeds).