how big garage door opener should I buy for a double garage?

[RoseInSnow]

I saw one is 1/3 (or 1/2HP) with chain for around $200, one 2/3HP with belt for around $399,they are craftman brand? Which one is good for a double door garage? Do you think they are expensive? :Thanks:

 

[楚歌]

The more horsepower, the better. I believe you can use a 1/2 horse power, but if you do not want it to break soon, it will be safer to use one with at least 2/3 horsepower.