Trying to pick the best camera.. Advise?

[John Beattie]

Hi All,
I'm looking to up grade to a new camera. I mostly shoot surfing and beach scenes. I've out grown my Sony FX 1000. I've been researching and can't find a camera that meets all of my needs in my price range.
Considering 99% of my shooting is at the beach, having enough light is not a problem, back lighting usually is a problem. I estimate the price range I can afford is $3-4k ish. So what I'd like to have in a camcorder is;
1080p @ 60 fps
interchangeable lenses
clean hdmi out ( so I can add an external recorder like a Ninja in the future)
recording with the best codec for the price range (pro res would be nice)
nd filters built in
and a camera that has minimal problems with rolling shutter.
Any suggestions?