What can be a good online brokerage for me? PLEASE suggest!!

I haven't used online trading ever before and till now, I've used a traditional phone broker. But now, I'm thinking of trying online trading, for the first time.

I'm NOT a day trader, I don't do intraday trading and I invest only in equities. Basically, I use a capital of around 3-4 lakhs, that I invest with a horizon of around 2 weeks (or, at the most, may be 1 month) and within that time, I sell off what I hold, book profits or losses. And then invest the same principal amount again. And so on.

I have mostly been thinking about starting a Demat and Online Trading Account with HDFC Bank (called HDFC Securities), where I already have a Savings account. The 3-in-1 facility and easy fund transfers look good. Since it's one of India's largest banks, I feel my money will be safe with them.

Will HDFC Securities be a good option if you look at my investing method? And is online trading complex/hard to grasp for those who're new to it?