Well real question or not; here's my take.

If you only had a few requirements; and any mail order bike fits your needs - go for it.
But in this case you have a list of requirements; some of them can only be answered by
riding the prospective bike. Rides well, able to handle varied terrain, etc. These can only
answered by riding the bike. So my suggestion is to visit a local shop; or test ride a used
bike from Craigslist.

Most bikes with the Dahon type fold/break in the middle will fit in a standard suitcase: