My luggage recommendation is to check out the local Army Surplus Store and see what they have.
More than 10 years ago I bought 2 "parachute bags", which apparently are used for packing parachutes in (so I'm told). They're a heavy denim-like material, drab green. I painted them both with fabric paints, one has flowers on it and the other has Disney characters. I've used them on every single trip I've taken since then, and they're in fantastic shape. I've even tossed them in the washing machine.
I figure anything for use by the army is meant to be thrown around and hold up under stress. And these things sure have.
Plus they fold right down flat, so they take up very little room. And they hold an incredible amount of stuff.
Easily personalized so it's a snap to tell what luggage is yours.