Size of Sims 3 Store Worlds

I'm very interested in having a Sims 3 world with all (or at least most) of the expansion pack lots, however, you need a world that's very big in order to accommodate all of them.  I wanted to use an official one so that all of the appropriate spawners would be in place, however the store does not tell you the actual size of any of the worlds or the number of lots on them.

Is there anywhere you can find out the size of the purchasable worlds and the number of occupied/empty lots before purchase?