Yes your GPU should fit in your case, as they claim it will fit full sized GPUs. The 2nd GPU fitting with the first one will be based more on the motherboard. And according to the motherboard manufacturer it will fit...however you have to think about the decreased spacing between GPUs that will cause them to run hotter. And how well the two GPUs would fit also depends on the actual thickness of the GPUs. So while it should work, the fans of the one GPU will be blowing the hot air directly into the other one...and there will be small space between them...so one card will run quite a bit hotter than it should because of that restricted air flow and the other will run hotter because of the extra hot air it is getting from the other one.
Since you don't plan on overclocking, I would definitely suggest you go with something like the Cooler Master Hyper 212 EVO because it works better than the stock CPU coolers you would get and does not take up a ton of room. And regarding your budget and build, I noticed that the selection of parts you linked to did not include RAM, PSU, HDD/SDD, or an optical drive. Not sure if you already have that stuff or not though, but thought to just double check with you.
Honestly, I have a GTX 780 Ti variant right now and had been considering to go with another one for SLI in a couple of years...but am leaning towards going with a super powerful GPU for 4K gaming then while using the 780 Ti for running 1-2 non gaming displays. Considering your budget, travel requirements, and overall system performance expectations I would honestly suggest probably going with a much cheaper motherboard that runs only a single GPU and making a beast for the money. You don't really need much of a motherboard right now, and you could get a sub $100 one that meets most of your requirements that would probably work better for your build.
After replying to your message initially I had spent a bit of time thinking about what I plan on doing with my upgrades in about 3 years and you have to consider that DDR4 RAM will be out, as well as clock rates on CPUs will be higher, and GPUs will offer more VRAM. There will always be something better, and definitely am not saying to go super cheap right now to build again in 3 years. There will be noticeable gains in components at that point in time, but not worth upgrading most of a system...with the exception of course being a GPU.
With all that being said, I would probably advise you to go a different route. For example, I absolutely hate how GPUs are sideways in computer towers, but I tolerate it because I don't move my system anywhere. However that is a lot of pressure on the connectors, and when I end up moving in a year or two and having room I am going to build a custom PC/server cabinet in my man-cave/bedroom so I can have the motherboard flat and the components such as the GPU connect more appropriately. I do not care for the square computer cases overall, but with the idea of you moving it around, you should really consider one so that your components can fit together in it better (less stress on them for moving anyway).
And I would recommend you go with a single GPU motherboard to save money...unless you know for sure you plan on running more than 1-2 displays at beyond 1080p in the near future. This is about what I would do in your situation if I planned on moving around a lot and wanting to game or do some video editing at 1080p on 1-2 displays:
PCPartPicker part list:
http://pcpartpicker.com/p/Y2swyc
Price breakdown by merchant: http://pcpartpicker.com/p/Y2swyc/by_merchant/
CPU: Intel Core i7-4790K 4.0GHz Quad-Core Processor ($339.98 @ SuperBiiz)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($29.98 @ OutletPC)
Motherboard: Gigabyte GA-B85M-DS3H Micro ATX LGA1150 Motherboard ($63.99 @ Newegg)
Memory: Kingston XMP Blu Red Series 8GB (2 x 4GB) DDR3-1600 Memory ($75.71 @ Amazon)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($52.91 @ OutletPC)
Video Card: EVGA GeForce GTX 780 Ti 3GB Superclocked ACX Video Card ($689.99 @ Micro Center)
Case: Fractal Design FD-CA-NODE-804-BL MicroATX Desktop Case ($109.99 @ Mwave)
Power Supply: SeaSonic 620W 80+ Bronze Certified Fully-Modular ATX Power Supply ($88.99 @ SuperBiiz)
Operating System: Microsoft Windows 8.1 (OEM) (64-bit) ($89.98 @ OutletPC)
Total: $1541.52
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2014-07-31 17:38 EDT-0400
I did not know if you needed or wanted an optical drive. You can install a slim slot loading disc drive into this case if you want to...I don't really have any recommendations for brands of those that are good so you would have to probably open another forum question for opinions. Otherwise this setup does offer a powerful system, you can upgrade the RAM but not the number of GPUs (it only supports one). It comes with three fans pre-installed but you may want to add at least one more so there would be two on each side...its up to you and what temperatures you end up getting.
Anyway, just my two cents...figuring that a square case would help the components get a bit less stress during constant moving as well as allowing you to box it up into a hard protective case easier.