My boyfriend (and more or less, me!) has this tank:
The tank itself is quite good, strong and all that. The hood is dual-bulbed, which is great as well. The filter is fine.
Filters and bettas (unless you plan on having other fish) arent really friends.. youre going to have to baffle the daylights out of most filters to keep the heavy-finned betta from being pushed around.
All that comes with the kit, which is great. We have a 25w marineland heater (adjustable) and we love it. It keeps the tank SUPER steady, even when really cold.
Its divided into 2 5 gallon sections, heater on one side, filter on the other. We have it all-natural, natural looking gravel and only live plants.
If you're thinking of decorating, live or not (though live is great!) consider getting a large center piece for the tank and planting around it. Petsmart has large (fake) driftwoods that look awesome, including one that looks like the base of a tree. I want one sooo bad!
This is the one that I really want-- it looks SO GOOD! Even in person!
(oh, if youre thinking of going live! http://www.bettafish.com/showthread.php?t=76428