Best setup for long distance?
We don't give specific product recommendations here on Bicycles.SE. I will mention that because they are produced in smaller volumes, recumbents usually will be more expensive than conventional bikes with similar specifications.
Long-distance riding is not a great use case for electric bikes: you'll run it down before you get where you're going and will then be hauling the electric system as dead weight. Or if you use it intermittently, you'll be hauling it around as dead weight the rest of the time. And you'll need to arrange to recharge it where you're going. You would need to compare the prices of buying a bike with electric assist built in vs buying an aftermarket electrical system. I suspect the aftermarket system would be more expensive overall. It would not be as well integrated.
There are tandem recumbents, but you can't just stick a seat on the back of a single recumbent.


If you're new to long-distance riding, you need to acclimate to it, and some minor changes to your current setup may make it more comfortable.