Yeah, pro digital bodies are rather shocking in price. Ironically many people who dumped 8K on the first Canon 1ds were rather disappointed in many ways as many lenses just did not work well (especially wide) with the sensor and produced dramatic light falloff and color shift at the edges. This remains somewhat, but less true, with even the latest sensor which is one reason Nikon IMO has stuck with the smaller sensor.
It took me about a decade to realize that one can not put 2000 cubic inches of gear in a 1000 cubic inch pack
I was completely convinced that somehow it would fit! I still relapse at times.
There is a company called Delsey that makes a bag (Pro Trolley 52).
www.delseycamerabags.com
I have never seen one in person, but it looks like it is about as big as one is going to get for carry on, it does NOT look like a camera bag (rather more like luggage) which IMO is a good thing, it has padded dividers specifically for camera gear, has a padded laptop compartment, has rollers, and IMO looks to be about as close as one is going to get to meeting your requirements. B&H photo sells these.
If you purchase one, let me know what you think as I've been looking at these for a while, but can never find them locally to check them out.
Will this hold all you stuff? Unlikely, but then see my comment about stuffing an elephant into a Yugo....
You're going to love the D2x. My best advice is shoot digital like slide film (don't count on a ton of exposure latitude) and use the heck out of the histogram. If you are blowing highlights, reshoot, as no amount of digital magic can save blown highlights.
I try to shoot in camera (just like film) and do as little cropping and post processing digital as possible which still means I tweak just about every image
The camera has a TON of settings and options. My approach to most is to shoot as nuteral as possible (don't up the saturation/Tone/Hue in camera) as Adobe handles post processing very well, but if one punches up the saturation to clownish levels it camera, it can be difficult to correct post, and it's very easy to perform the opposite with a low saturation image.
Don't expect your initial images to look like Fuji Velvia. Most new to digital shooting DSLR's are rather unimpressed with the less punchy starting image, but those can easily be processed into crisp standout colorful results. I think of digital as shooting with a low contrast film (actually many of my portraits can go strait to print). But add a bit of saturation/contrast to a landscape post process and the colors come alive.
Have fun, and I'm jelous of you new setup.... I'm planning on an upgrade to the D2x, but can't seem to find that 5K I put in my wallet..... Maybe by end of the year.
L8R
