I have interesting in your project and I belive I'm the proper one on this project. I'm a sales in a electronic manufacturer in shenzhen which produces controller and high voltage power supply. I also help a South Africa company sourcing and following whatever items they need for over 2 years. I also sometimes take the customer to visit or audit factories in China. In order to handling easier, I registered a company and can do business freely. Regarding the charge, generally, it depends on the value of your project. I can earn my commission. Of course, if you like a rated pay, it is fine for me too. Thanks.