I'm not sure I can make a good recommendation for an expedition tire because it all depends on the overall conditions expected during the trip. Overall, I do agree that you want a strong tire with a relatively hard compound, very strong sidewalls and good load rating. There are several Michelin tires that fit that bill, but they're relatively hard to find in the US and expensive when you can.
I will tell you one thing; if you're building a dedicated expedition rig and plan to cross borders with it, 17" rims is *NOT* a good size. Yes, you'll get better handling on the road, but finding a 17" tire in remote areas will NOT be easy and in other countries, you can forget about it. They may be all the rage these days and come OEM with many different vehicles, but they're still very rare elsewhere. I'd stick to 15" or 16", the latter for a better load rating and better handling.
Editor, South & Central America
'99 UZJ100 Toyota Land Cruiser