Risk profile graph is the same as being short. Change the risk profile by buying a call at a higher strike price and selling call at lower strike price. Google credit spread.
You can get portfolio margin at www.interactivebrokers.com which gives you 6x buying power with a $100,000 account. They also have the lowest interest rates.
Use esignal to send orders to IB. Version 12 of esignal is the slickest front end I have seen. If esignal is too expensive then use www.medvedtrader.com For $19.99 a month.