You probably won’t find what you’re looking for except from either a high-end furniture store or from a custom cabinet maker.
Almost anything you find from a chain store or online will be either RTA (Ready To Assemble) or built from particle board and held together by staples. Both are inherently weak and will eventually fall apart.
If you have to go either RTA or particle board construction, screw it to the wall studs to give it rigidity. Any flex or movement is what causes them to fail.
I like the Williams-Sonoma Swedish wood shelving. It would have cost over $700 to do ours using their product. I found almost the exact same shelving at Target- this was about 6 years ago. Hubby installed it and even made a wine rack using scraps from other projects- all for less than $150.
Here is the Wms-Sonoma pine shelving.
http://www.williams-sonoma.com/products/swedish-wood-shelving/?pkey=e%7Cshelving%7C16%7Cbest%7C0%7C1%7C24%7C%7C1&cm_src=PRODUCTSEARCH||NoFacet-_-NoFacet-_-NoMerchRules-_-