First off, this isn't an installation question, and the POSTING IN THIS FORUM post in the section you posted in should make it clear it doesn't belong in this section.
But secondly, I don't really see how other peoples' opinions of larger font readability will tell you anything you won't learn from simply loading larger fonts until you find one that works, then picking/making a theme that uses one at least that large. If I've misunderstood your intent, perhaps you could clarify?