Did you turn down the water flow of the Whisper filter? I said before that my Whisper filter was called a mini. I looked at the box and it's called a micro filter. Anyway, it has a sliding switch on the back that you can slide back and forth for more, or less, water movement. There's a triangle design on the switch -- slide toward the triangle point and that's the setting for the least amount of water flow. If this setting still provides too much water movement, check out the Small World filter or Azoo palm filter. I'm wondering if the mini Eclipse filter would be the same as the Whisper filter you have -- too strong for a 2 gallon tank.
I looked at the Jungle website for the tank warmer you mentioned and didn't find one. I think (not positive, because I don't have one) that tank warmers are for reptile tanks. I have seen the small heaters that megladonsharky mentioned at Wal-Mart, and I have the small Hydor heater, linked by jibboo earlier in the thread. I like the Hydor mini heater, but you have to follow the directions and not place the tank under a light or the water will get very hot, about 90 degrees.
My bettas eat the Hikari Gold pellets and freeze-dried bloodworms. I soak the pellets in a cup of tank water for about 2 minutes before feeding them to the bettas, and I soak the bloodworms for about a half a minute. Dry foods can cause bloating if they are not moistened first; otherwise, the food can absorb moisture in the fish's stomach and swell up.