Bettas can go up to a month or so with no food. So I doubt he will starve to death. I feed mine Hikari Bio-gold and Wardley's. Flair refused to eat Top Fin. Keep offering him food. Give him time, he probably needs to adjust to the water temperature or something. He'll eat eventually :)
And my 25 watt I mentioned earlier was Hydor and it did fabulous. I have it in m 5 gallon currently and it's worked great for me.
My 25 watt heater actually came with the tank off Craigslist. But my other tank has my Hydor 50 Watt heater and I got that at Petsmart for cheap. I do remember seeing the 25 watt there too though. They both have the adjustable knob for temperature. I was afraid to buy one that didn't have that because I am gone most of the day and would have no way of monitoring the temperature.
Spaz is eating! I'm happy and feeling relieved to see him eating again =)
But now I think I need to clean the tank cause it looks like it got all foggy and it's never done that before so I'll probably clean it. I use NovAqua+ and AmQuel+. They smell so horrible but it seems to be doing good. lol