Buyer/purchasing agent with knowledge of electronics

We are looking for a long-term buyer/purchasing agent with knowledge of electronics. We make prototypes and small batches (10-500 pieces). Our devices include touch screens, single-board computers, batteries, LEDs, and small circuit boards. We are also working on smaller devices. Sometimes you will help us choose prototype parts. In this case, the price of a large batch is not very important, but how to get one or two pieces quickly and reasonably for testing. The main work is to ensure that the parts have the necessary features and that they actually work. For example, we currently need a PowerBank + trigger-USB cable that supports PD/QC fast charging, so that we can get power out of both 5V USB cables and 12V USB cables, with sufficient amperage in both. A test batch (5-20) means that we are looking for a good supplier from whom we can get a high-quality large batch at a low price. If the test batch works well, we will move on to making 50-500 piece batches. Larger batches are redesigned separately. We primarily use Alibaba, especially when making test batches. We make larger purchases directly. We only use suppliers with Trade Assurance. Prototype parts are often best ordered elsewhere, unless you want to prepare for a test batch. Your work is transparent. Especially in the case of Alibaba, we use a common user name when negotiating the trade, and when ordering, we switch to our own user name. In your reports, you will tell us about suppliers from whom you have asked for products and their answers. We will pay you for your work, we will not pay commission on purchased goods unless otherwise agreed in advance. A bonus for well-functioning parts is possible afterwards. It would be good if you can help with quality and shipping inspection, but we can order it elsewhere if necessary. Because we receive a lot of offers from automatic bots on Freelancer, we ask you to start your response with the words "Good evening" so that your message stands out. Similarly, if you can help put together shipping for multiple parts from different suppliers, that can also sometimes be useful.