About the filter - I had a problem with my betta getting sucked up in mine and someone on the board suggested a foam pre-filter to put over it. It kinda looks like a spongy cylinder. Fluval makes a great one for just a couple bucks at pet supplies plus, though I'm sure you could find something similar at any pet store.
Anyways, cut my current down a lot, still filters the water (debris gets sucked to the foam, so I just rinse that during water changes) and I don't have to worry about any of his precious fins getting caught in the filter should he drift to close to it.
Tank looks great - nice and roomy for him! With that much space you can do some amazing decorating and really make it look quite nice.