You could find many manufacturers at Alibaba too. In my opinion, there are not better or worse site, but it will depend what company you choose to buy from.
My suggestion is: if you are going to buy electronics, buy them from Shenzhen in China Mainland or Taiwan. But anyway, take care about fakes. In China 99% are replicas, fakes, or whatever you want to call them.
If you are going to buy small quantities, forget about China. Search good suppliers in USA. It will be more safe for you, and if you go deep in your search, maybe you buy cheaper than China.
But, you will need to work hard...to find good ones. Just try small quantities to start.
On big quantities, ok, contract a trading company and take a plane to Taiwan, China, Hong Kong.