Black and Decker make a toolchest that has wheels on one end and an extendable handle on the other. The wheels might be a bit small for what you want, but they're definitely bigger and sturdier than roller-skate wheels (I'd say about a 4" diameter, maybe 2" in width). I bought mine at Rona in Calgary.
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"The mind is not a vessel to be filled but a fire to be kindled."
-Plutarch