Krystal has one of those starage shelves (dora) they are good, but as rach said, the tubs are very small.

i think look at ikea, they seem to have different storage systems.

krystal has two big toy boxes (both wooden, one we unscrewed the lid so everything is just there ready to play, and the other is a bookcase with the toy box instead of a bottom shelf.) these work well for us!

i also have a few large round baskets with handles (which i bough for $20 from the cheap caneware shop up here) i did plan on using one for the bathroom - towels rolled up in the basket. but ended up filling one with books & one with 'smaller' type toys (the stuff that gets lost in the bottom of the big toy boxes!)

i think your idea of low bookshelves with tubs is great (or you could buy square/rectangle baskets or something similar to match your loungeroom) you could alternate the positions of the tubs once a week or so, for some variety! (i often change around our toy set up, as ive realised Krystal plays with what is most visible)

wow i have rambled!
HTH!