I'm not Keith but could wax poetic for hours on the subject of tool cabinets.
Short version of my nsho is the consumer-grade import boxes are inexpensive and very effective for light drawer loads and infrequent use, but weight kills them, fast. The cheap slides bend and break down, the thin metal bows, warps, cracks, and splits, the slide tabs fatigue and break off, plastic slide stops fail, and heavily-loaded drawers become very recalcitrant immediately. Sooner or later a cheap box worked hard will hurt you.
Waterloo used to make a good, reasonably affordable line of drawer cabinets configured and sized for storing frequently-used machine equipment and tooling (not mechanic's boxes), you might look at those too.