5gal buckets are the way for food, honestly. They have much less of an issue with structural integrity when stacked. Totes are much better suited for lighter stuff.

As for shelves, I would recommend keeping an eye for sales on these from Amazon. They're the best price/performance I've found personally, and have no issues holding the advertised weight. You can set yourself a price alert, watch https://www.preppingdeals.net/ , or sub to /r/preppersales to see when they go on sale (usually for around ~$45-55 every few months). Either the 4 or 5-shelf variant are good, although I'd recommend using the wall mounts if you put any amount of weight on the higher shelves of the 5-shelf version.

Most of my storage has been converted to looking like this. You can keep it well organized, and there's no issues with weight.