Swing trading futures/stocks in marginable account?

Margin or Margin plus trading is generally related with daytrading or BTST. But that is too much of 'glued to screen' type trading for me. I am more interested in swing trading, holding futures(nifty or single stoks) positions for 1-3 weeks time period.
Which brokers(sharekhan, zerodha, icici etc) do allow to hold delivered positions for long holding period for futures or stocks bought on margin. I am ready to pay reasonable interest(8-12%) on margined money.
Loan against securities can get me margin of say 50-70% of securities value. But there are limitations for selection of scripts.

Similar threads

Zerodha – Open Paperless Account

Open online account with Zerodha. Free delivery trading and Max Rs 20 for Intraday, F&O, Currency and Commodity Trading. Intraday High leverage with MIS, CO and BO.

Are you a day trader?