I have this tank. It generally wouldn't be my first pick for a betta, but I can tell you that the filtration is extremely gentle. The system pumps water up the intake tube through the spraybar, which empties onto a filter pad and other media. Then, the water flows to an area with a hole cut out so the effect is kind of like a very gentle toilet bowl, for lack of a better description. I think it could work fine if you have resting places higher up in the tank like others suggested. The lighting is sufficient for a nice low light planted tank, if you like plants.
*edit* Here is a link to my tank. I have pics of the filtration system in case you aren't familiar with it.
8 gallon JBJ 180- pics