I had a Eureka Solitaire and I didn't really like it all. It's hard to get in and out of, and there is no room for anything but you lying down. For a trip like yours I'd certainly want something bigger.

You should look into what long distance and through hikers are using. I can't help with that much, but I do agree that a free standing tent that goes up fast is what I'd chose. One with two poles that cross in an "X" and has a vestibule to put your pack under. That design is hard to beat.

That's a mighty ambitious trip you're planning. If you don't mind I'd like to ask a few questions...

Have you ever made the trip east of the Mississippi to the west coast?

Have you done, or do you plan on doing, some shake out trips before you head out?

Have you planned a route?

What is it you want, and what do you expect to get from this trip?

The reason I ask is because I've made the drive from the west coast to the Mississippi on North, South, and Central routes and all of them have very long and desolate stretches with little or no access to public water or land designated for camping, and a huge amount of what's there isn't what I'd call a scenic wonder, and your options are still wide open.

You see, there is a vast amount of experience here you can lean on to help with you getting to whatever your goals are and you might benefit from sharing them.

I'll offer that there are many places you can go to immerse yourself in the solitude and natural beauty and local culture with the time you want to spend, but a coast to coast tromp across the U.S. isn't that.

That's quite a different trip. I'd say it's more of a physical endurance and self deprivation kind of trip, and it's almost certainly going to involve some "stealth camping". You need a different plan for that kind of trip.