I just used the A6000 in salty humid and sandy environments in Galapagos for the last two weeks with no problems.
To my best information the A7 has better sealing than the a6000.

Works great with my Canon 70D. Should work as well with Nikon.
Just used it on a trip to Galapagos.

Don't forget the beauty stays inside, what's outside gets weathered :-) :-) :-)

Look at the 7100. Seems to be a serious camera below $100 body only.

Intend to take my Canon D70 with Canon 15-85mm and Tamron 150-600mm
And Sony Alpha A6000 with the kit lenses (16-50mm and 55-210mm both with OSS).
I would appreciate any practical advice and comments.

Happy 2015 to everyone on the Hedgehog!

If your budget is limited I would go with the a6000 which is an excellent camera and a very decent trade-off ($$ vs Performance). You can get a package with 16-50 and 55-210 mm lenses for about $750 and use the difference to what you'd pay for a Nikon body to buy a couple of (limited options) quality lenses that fit your photography style.
Take a look at Gary Fong's video on a6000 at B&H website.
I have been a Canon guy from the days of film, and I had to make a similar decision decision recently how I spend my limited photography budget. After much analysis and debate with myself I decided Sony. It is a new learning experience that takes you to new territory.
I believe Mirror-less is the future of DSLR and Sony is a recognized leader.

Feel free to contact me should you need more information on my process.
BTW you can not go wrong with Nikon if you have the $$$, they have some great cameras (the D750 and the 810D) I wish I had.
Good luck in your decision

Look at Costco. They have a package deal with 2 lenses , memory card and bag for $1299.
http://www.costco.com/Canon-EOS-70D-DSLR-Camera-2-Lens-Bundle.product.100129567.html?catalogId=10701&keyword=canon+70D&langId=-1&storeId=10301&refine=

You can use an inflatable travel pillow or neck pillow.
Easy to carry and travel with and you can inflate it as much as is comfortable to you.

The smallest of the LowePros you can use for the stuff you listed is LowePro Pro Runner 200AW . I stuff in the LowePro 200AW 2 Canon cameras(7D&70D) 2 zoom lenses, one Prime ,Flash, spare battery with charger. If you take only one camera you can take another lens. It has room for memory cards and accessories in the front and in the interior pockets. Very convenient for travel as it fits under the seat of any airplanes if you take it as personal item on board. It has a weather cover hidden at the bottom.
I may put mine for sale in a week.
Good luck!

These are good questions, and the 7D limitations are well known (I can list them if interested), and if cameras compare to cars , I like driving and want to enjoy many newer technological advances. (like all wheel drive CVT transmission and X-drive.....)

These are wonderful pictures. Could you share what settings did you use?
Thanks for sharing!
nsilberma

Thanks for your comment. I am not looking for a $500 camera. 7D was a great camera for it's time, though still usable for certain types of photography, it's got its limitations that puts it behind the technology and and performance curve.
The MK ii has some nice enhancements like the dual pixel AF and in general better AF functionality, 65 points cross type AF, 10 fps, weather sealing, dual memory card, borrows some features and performance from 1D and 5D and more. The place where I am in doubt is in the misses area: No touch screen, no wifi, noise or SNR performance (slightly better than 7D), Dynamic range and Image quality (though subjective).
I will look at real pictures taken in different situations by others to figure out my trade-off point.

I really meant the price of the MKii (about $1800) +/- 500 which makes it in the range of $1300 to 2300. I would not go for anything below the original 7D which I still love.

I used the 7D for about 5 years and looking to upgrade. I was looking at the new MK ii and have doubts. Since I am not a sports photographer neither a big fan of video, the improvements in the other areas seem to be marginal and not convinced worth the money. I like a number of new features and improvements, but the camera is rated only 70 on Dxomark.com with mediocre IQ rating. Are there any cameras (any make) that could be an alternative with better DR, IQ and ISO to compare within the same price range +/- $500?