OM-D EM-5 Plus What Gear (Lenses, Flashes, etc)?

Hi folks,

I've got an Olympus OM-D EM-5 (Black) with the 12-50mm kit lens on preorder. I'm really excited by the potential of this upcoming camera.

Now I need some help on the other stuff (lenses, flashes, etc).

So far this what I'm thinking:

• FL-600R Flash

• HLD-6 Battery Grip

• Panasonic 100-300mm Lens

• Panasonic PZ 14-42mm Pancake Lens

Are there Olympus lenses that would be better to go with over these Panasonics?

And while I think the 14-42mm Pancake will make a GREAT everyday use lens, I'm thinking I might also need a good prime.

I'll be taking all kinds of pictures (landscape, street scenes, people, etc). Is there anything else I'll need to pickup. I've already go a couple of tripods and cases.

Thanks

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Canon T70, AE1, Rebel2000 G1, G2, G5, Pro1, SD500