Canon 5D Mark 2 & Nikon Dslr?

Which as Nikon D800 & Canon5d mark2 suggest in best studio & Wedding photography shoot image

Are you sure you don't mean the 5D mark 3? The D800 is better than the mark 2 in almost every respect, but particularly for image quality, resolution, colour depth, dynamic range and number of focus points.
http://snapsort.com/...Nikon-D800

Even against the 5D mark 3 the D800 scores better for image quality, colour depth and dynamic range. The 5D mark 3 has a faster motor drive and higher ISO, but how many times do you need 6 frames per second at a wedding - or to shoot above ISO 6400 for that matter?
http://snapsort.com/...Nikon-D800

For a wedding photographer I'd have thought that image quality was the most important, so the D800
is the obvious choice.

Go for Canon 5D Mark

I would go for the D800 for the same reason that Martin gave.

As opposed to most people on here, I actually am a working wedding photographer.

I shoot Canon, I've shot with a 5D Mark II in the past, I currently shoot with a 5D Mark III, 1DX and 1D Mark IV.

The 5D Mark II is a phenomenal camera, but it's a 4 year old camera. Advancements have been made since then, the 5D Mark III holds its quality much much better.
The D800 is a beautiful camera with fantastic dynamic range but a 36 megapixel image is ridiculous for weddings. I'd shoot around 2, 000 - 3, 000 shots per wedding. Already I find the 22mp sensor of the 5D Mark III to be too much, the files are too big for what I need. The D800 will be a terrible waste of space and you'll have to put more money into buying memory cards.

As a studio photographer, the D800's resolution would probably pay off, especially when it comes to fine detail and skin smoothing.

Go with whichever manufacturer you have already invested in. I have about €30, 000 worth of Canon lenses that I've invested in over the years so there's no way I'm going to ditch Canon just to buy a better camera body. The lenses are the real reason as to whether or not your image is good. You need good glass to go in front of a good sensor to make good photos.

The 5D Mark II