You're describing pro quality gear, but it isn't available new on a beer budget. There are not a lot of fully ruggedized, weather sealed bodies and lenses on the market.
I would probably look at the Panasonic Lumix GH5, with Panasonic Leica 100-400 f/4-f/6.3 zoom (same field of view as a 200-800mm zoom on full frame dSLR or 35mm film). Add some shorter lenses for indoor work. My selections would be the 8-18mm f/2.8-f/4 Panasonic Leica zoom, the 12-35mm f/2.8 Panasonic Lumix GX-Vario II zoom, the 30mm f/2.8 Panasonic Lumix Macro lens, and the 35-100mm f/2.8 Lumix GX-Vario II zoom. But over 90 lenses are available from at least four manufacturers. This is a link to 85 of them available as of July, 2017:
http://hazeghi.org/mft-lenses.htmlEven if you stay within your budget and buy used gear to do it, I would look at Micro 4/3 for several reasons:
First, you said you want a very rugged body. The GH5 is freeze protected to -10°C. It is water-resistant, dust-resistant, and has a titanium, die-cast chassis. The shutter is tested to 200,000+ actuations. Many pro-class, weather-sealed lenses are available for it. It features excellent still image quality and excellent 1080P and 4K video quality. People can and do make independent films with these. Pros use them for portraits, hybrid photography, events, weddings, advertising, travel, documentary work, magazine covers...
The predecessor of the GH5, the GH4, was rated #1 in its category (Mirrorless) by Consumer Reports in their just-released 2018 Buying Guide. The GH5 is a much better camera than the GH4.
Your intent is travel photography. A Micro 4/3 kit will save you 2/3 to 3/4 of the size, bulk, and weight you would have with a full frame dSLR kit, and roughly 1/2 the size, bulk, and weight of an APS-C/DX dSLR kit.
Micro 4/3 pro glass can be a little more than half as expensive as full frame dSLR glass. It is nearly always less expensive.
For instance, the Canon EF 70‑200mm f/2.8L IS II USM Lens costs $1900. The Panasonic Lumix G X Vario 35-100mm f/2.8 II POWER O.I.S. Lens costs about $1000. Both have roughly the same field of view zoom range. Both are image stabilized. Both are f/2.8 fixed maximum aperture zooms. But the Panasonic works with the GH5's internal DUAL image stabilization system to provide 5.5 stops of stabilization, compared to the Canon's 4 stops of in-lens only IS. The Canon lens weighs about 1490 grams. The Panasonic lens weighs about 357 grams — That's less than ONE FOURTH the weight!
Want another example? The Canon EF 85mm f/1.2L II USM Lens costs about $1850. The Panasonic Leica DG Nocticron 42.5mm f/1.2 ASPH. POWER O.I.S. Lens (again, with the same field of view) costs about $1400. The Canon lens weighs 1025 grams. The Panasonic Leica lens weighs 425 grams. Both of these are extremely high quality lenses.
I won't lie, you DO give up a little dynamic range and low light capability with Micro 4/3. The best dSLRs are about two stops less noisy than the best Micro 4/3 bodies. The "speed limit" for most people using full frame dSLRs seems to be around ISO 12,800. The "speed limit" for most people using Micro 4/3 cameras seems to be around ISO 3200. For APS-C and DX cameras, it's around ISO 6400. I've used my Lumix GH4 (predecessor of the GH5) at ISO 5000 with acceptable results (Thats about like ISO 20,000 on a full frame dSLR, or 10,000 on an APS-C/DX camera). But if I were doing spy work, yeah, I'd want the full frame beast (and an assistant to carry my gear). Fortunately, I need an ISO higher than 3200 about 1% of the time. I'm not going to own or carry a full frame camera 100% of the time for 1% of my work.
I also don't make huge prints very often, and I avoid pixel-peeping photo competitions like the plague! Over 98% of what I do is printed smaller than 18x12 inches. 95% is smaller than letter-size pages. 90% of it is viewed on the Internet or corporate Intranets, on smartphones, tablets, and computer screens. Some of it is projected to billboard size, but viewed from over 50 feet away. Much of it is a hybrid combination of stills, video, text, graphics, and sound. But it is all recorded with the GH4.
Here are a few links worth your time:
https://www.dpreview.com/reviews/panasonic-lumix-dc-gh5https://www.youtube.com/watch?v=1UhcXk4owuU&t=1shttps://www.youtube.com/watch?v=HfqtqoGpn8I&t=1shttps://www.youtube.com/watch?v=kh-HctljNj4 (hour-long, detailed review, still photography features are about 2/3 of the way through)
You're describing pro quality gear, but it isn't a... (