Utricularia 'Big Sister' is a great form of U. reniforumis. U. 'Big Sister' consistently produces large leaves unlike most other U. reniformis forms which commonly produce many small leaves. I grow this plant in a peat:perlite mix but many have better luck growing it as epiphyte, I've never tried it so I really can't comment on it. Plants listed for sale will be shipped potted (in 2.25" to 3.5" pot) and only after it has (at some point) had at least 2 pads out at a time, as shown in the photo. I have no idea how much growth is under the media though.
You can see more information on my growing this plant (and pictures including of its flower) here: www.terraforums.com/forums/utricularia-aldrovanda-genlisea/121594-reniformis-sister-yep-flower.html