You want to be careful with the fluvals as I read in other posts that some betta's were having trouble finding the small area with the air pocket (this is the fluval edge tanks). It seemed to be hit or miss (depended on the specific fish). Other owners just decided to not fill the tank up all the way to the top, but this kind of took away the appeal (and reason) of getting a fluval edge in the first place.
I purchased an Aqueon Evolve tank. You should check that out as another option. From what I've researched, people seemed to be happy with the tank (the one recurring problem was that people received tanks that had scuff/scratch marks on the acrylic, so you should spot check the actual tank prior to buying).