I have (and use a lot) a Sigma 8mm circular fisheye. I've used it on Dx and it gives results like this on a Dx body (D200 in this case).
One thing to be aware of (doesn't affect the OP since I'm pretty sure both his bodies are proper ones with the AF motor in body rather than the gelded later, entry level ones that rely on AF-S etc lenses) is that the f/4 version (IIRC, there's a newer f/3.5 one available) isn't HSM, so needs the in body screwdriver AF motor.
CLICK HERE for a link to Sigma's page on the current lens - it seems from the name and letters following it that this lens is also screw driven. It's also reminded me that it's the only 8mm with AF, although that's hardly necessary since DoF is massive, especially stopped down! Flare is incredibly well controlled as long as the front element is kept scrupulously clean - if you want to use filters, they'll need to be gels, slipped in behing the rear element - not much good for grads or pols but with horizons often being curved, grads aren't really that useable anyway and with 180 degrees FoV, pols would give rather strange effects in the sky!
Even though I love it, I'm not sure I would pay the new price - I was extremely lucky to see one on the FS board on the forum for £220 inc P&P. I'd wanted one for around 25-30 years and finally found one I could afford. A quick look at the used dealers' ads in the back of AP doesn't show any 2nd hand and the new price seems to be £620 (bar a penny).
MPB may have one in stock - check their link on this site.
On FF, it gives a full circular image (any excuse to post this again - I love it!)
In that pic, the sun is just out of shot, top left of the circle - spot any flare (or flair!)
If you want to play at fisheye "on the cheap", I may well be selling my Lomo fisheye film camera (fixed lens, gives images similar to the Dx body pic near the top) on the board in the not too distant future. NO offers or attempts to buy it in this thread. :rules: ! Image from it below.
Every day lens? Probably not, although when I'm taking a lot of photos, I'll often take a couple with it, either to capture the whole site or for impact. However, it's not really an effect that can be replicated in PP. BTW, beware of feet and bellies/boobies creeping into the bottom of the shot! 180 degrees is wiiiiiiiiiiiide!