Fisheye for Nikon D3000?

I'm looking for a fisheye lens for my Nikon D3000 but I'm not sure which one to get. I'm willing to spend around $600 dollars, no more than $700, for one that takes excellent pictures. Please tell me which one I should get!

I have a canon t2i and i use the rokinon 8mm fisheye, it is for nikon as well, it is much cheaper 260, you could get the nikon 10.5 mm but that isn't as wide and much more expensive, but has a lower f stop

Here is a generic one:

http://www.overstock.com/Electronics/Rokinon-8mm-F3.5-Ultra-Wide-Aspherical-Fisheye-Lens-for-Nikon/4340547/product.html