[choke]

Ideally you want a rear hub that has the same spacing as your current one, otherwise you're going to have to adjust the derailleur every time you swap wheels.

As for tires, a lot depends on the terrain/surface where you ride so it's hard to give a definitive answer. Paselas work well on different surfaces and are pretty inexpensive but there are loads of options; Gravel Kings, Compass, Vittoria Pave, Veloflex, etc.