I want to open a children's photography studio. What output power is suitable for selecting flash?

It depends on the size of your studio. It also depends on what style of photos you want to take. As far as lighting is concerned, it is best to choose above 600W W, because the color temperature and output power are very stable. The photos taken are very transparent. This is your best choice. Disadvantages. 600 watts

Much more expensive than 400W. You get what you pay. So you have to think for yourself,

As for the brand, domestic Jinbei Helio is good. If you want a better capacitor lamp, it's not bad.