I've seen this question on here a bunch, so you might want to do a search to get more opinions and information. Most of the pilots I've seen use two ears, but some use one. depends on what you want. Since the flight attendant can no longer visit us, having an ear open for him/her is no longer important. I think I would feel strange only hearing in one ear.
I've seen almost every type of headset used on my airline, so it really is up to you. My suggestion? Use whatever you currently have until you have flown it a few months, and make your own decision. By then you will have seen a lot of people and asked their preferences. Hope this helps you out.