Where to buy Buck converter.

Hi, first sorry for my poor ensglish. I need to a 350 watts buck converter.
where can I find to buy a 350 watts buck, does it really response 350 watts or I should buy more than 350 watts .

For your Brushless DC Motor?
Two ohter threads already exist for that.


Reading your other threads, it might help if you explained the bigger picture of what the project is to do, what power source you plan to use and how you think you will be connecting it all together...