Obed,
Cabinet drawers and hardware fail for a few reasons.
Fronts coming off is a common problem. That is usually caused by someone slamming a drawer shut that has a heavy load in it.
Hardware failing because its overloaded, or cheaply made is another common problem.
I don't have any first hand experience using metal drawer sides, but I wasn't favorably impressed with what I saw in the link you posted.
Poplar is a good choice for drawer boxes. It has good straight, fine grain, it's strong, and it finishes nicely. Go with poplar drawer boxes, dovetail joints, and plywood drawer bottoms that are rabbeted in on all four sides. Some guys try to get by without rabbeting the back of the drawer. The bottoms sag with that set up.
The drawer slides they showed with the metal drawer sides looked like the cheapest of the cheap. Use only high quality full extension slides. I like the self closing slides that mount under the drawers. They have easy to operate levers that release the drawer for removal. Another thing I like about the under mount slides is they stay cleaner.
50% down is normal. I suspect the 40% upon delivery and 10% upon completion is because the cabinet maker doesn't want to be on the hook if you're not ready for installation when he delivers the cabinets.
Without having more details I wouldn't say 10% wouldn't cover the installation so I'm not going to say that pay schedule is unreasonable.
If you're not comfortable with the pay schedule you can try to negotiate a different one. Personally, if someone I haven't worked with wanted to negotiate terms that were much different than what I normally specify I'd probably tell them I'm not interested in doing their project....even in this lousy economy.
Jim,
Many if not most custom cabinet shops do their finishing in house.