For Wikipedia, I've been reasonably satisfied with Kiwix for software, and their updated-every-month-or-three copies of Wikipedia, and the related Wikimedia foundation sites, at http://wiki.kiwix.org/wiki/Content_in_all_languages .

If they average 1MB each, then you would need to shell out some decent cash

Unfortunately, I don't have "decent cash" to shell out. I've seem some setups at /r/DataHoarder that I would be extremely happy to ever own, but don't expect to until typical HDs are an order of magnitude or two bigger than today's. By which time I expect people will have come up with brand-new forms of data to fill the things with. :)

(Also, nice username. :) )

It's not just a nom-de-net, it's a way of life. :)