I started typing this out, then realized about two paragraphs in that it was going to be a lot of work, so I dug this link up which should answer some of your questions on orbits. (I learned something too: I'd never heard of a "Tundra Orbit.")

Short version: Low orbits decay quickly, but are easy to launch to. High orbits don't, but need more launch power and Van Allen belts come into it.

The ISS orbit is sort of a compromise. It needs constant orbit boosts (see this link) to maintain it, particularly since the ISS has one big-ass drag issue.

Willy Ley's famous space station had an orbit of around 1,000 miles, but that was published in 1958, which is the same year the Van Allen Belts were discovered.