If your going to get the bike in the USA it may be cheaper for you. (you dint fill out where your from)
The K75 BMW, R100s, F650 are old and a reliable but not the best choice IMHO. Good ones can be hard to track down some times and a other bike may no run you as much. Most of these have a "sit up" riding position.
The KLR 650 is a grate bike but roads, even dirt roads in the USA are in good shape. The KLR vibrates A bit more than most new riders like. The
DR 400 and DR650 are made like the KLR but are different in some ways. They have a "sit up" riding position.
The DL line fast and smooth but is no off road bike. They do run dirt roads with no problim. (I have a DL650) they have a "sit up" riding position.
All the above will get you all most any place on any road you want to go.
The "cruiser style bike" gust are not my thing. They tend to have little ground clearance and even less cargo capacity. I dont see many used for any real traveling. There riding position can be layed back to ungodly. One thing to wach out on them is how low there set up some will drag there parts off in even slow turns I see this time and agen.
Go to a moto dealer and put you bottom on the bikes before you decide try and take them out for a ride.
For the ride In the USA the camping is grate and can be free to more expensive than a hotel. (ran in to KOA "kampdround" that ran $40 a night I did not stay there)
Here are some camping links
Bureau of Land Management (4.2)
BLM land free to cheap
National Park Service - Experience Your America
National Parks some of the best places to go. get a pass here U.S. National Park Service America the Beautiful - National Parks and Federal Recreational Lands Pass
save you lots of money in the long run.
There are also state parks but Im not going to link.
If you get a used bike in the states and sell it you can save your self a bit
$ and can spend more on kitting out the bike. (seems a bit low to me)
$1,000 on gear just for you is a good start.
Panniers, top case, dry bags, tool kit, tank bag. You dont need them all but you will something to keep your stuff in. easy $1000 are so (I used saddle bags, and dry bags about $300 so you can get around it)
Another $1000 for tent, bag, sleeping bag, stove, cooking kit, and clothing. A bit less if you careful.
GPS well I want one to but with all the posting on the roads and a cheap road map of the area I dont see a grate need for one.
Look up some ride reports of the USA and get a better Idea of places to go how and gear. Heres one to get you going The Oasis Of My Soul » My Archives