Most successful teams have way more bleachers than I have though, can you tell me why?
The answer is most of them built their arenas before everyone realised it was better to have a higher ratio of LT. Or because everyone had lots of bleachers and people don't like to be different.
I'd much rather have your arena. When you are challenging for the championship in your country you will (almost) sell out, and you can then charge more.
I'm not even sure you really need to add seats. But if you want to, definitely they should be LT.