I am not experienced with them. Pontus Rex (that's his name) is my first Betta, and I've only had him for a little over a month now. What exactly is flashing? From your description it does sound like he flashes now and then. Is that normal?
I keep him on my desk, so there isn't that much room, but I have been wanting to get him a larger tank. I'm planning on going shopping this weekend and checking some out. As for his temperature, I have a heater, but it doesn't have settings, so I'm assuming this is as high as it will go. I'll look into purchasing another one.
One thing that will surely be in my budget is his food. I'll buy him one of those brands you suggested this weekend. Thanks for all your help!