Hello!
I can be very useful on what you need, because, I have experience doing that type of job you need. I worked with a US person more than a year concerning her amazon business.
I created listings, checking shipments to be in order, being in contact with a prep center that packed the items to be sold in amazon, checking the shipments from the prep center to amazon warehouse, getting best products to sell in amazon in online shops that had discount mostly on clothing for selling them in amazon in a convenient price pairing them to an existing amazon page or I can as well create new amazon pages to display new products to sell.
I also did some work similar of what you are requesting but searching products in alibaba and not DHGATE, my past client was kinda starting her own personal label, making bulks with not specific brand and selling them on amazon.
I think I can put your business on the go, managing 100% of the tasks needed because I have a good amount of experience on what you need. I'm also ready to be taught new requirements you need, I promise I learn fast and do things properly.
You can find 2 reviews about the specific amazon job I told you in my freelance profile from an employer named lpcherry.
Have a great day!
Sincerely, Rodrigo.