The right manufacturer or supplier of goods to sell on Amazon depends on what it is you want to sell. I’d start by researching the hot goods on Amazon. With your experience, you might already have some good insights on what sells well. Then I’d hit Alibaba, GlobalSources, ThomasNet, and other product sourcing and manufacturer listings. There are plenty of them out there and you can narrow the field with targeted Google searches. Plus, you might want to consider making private label versions of products that have sold well for you in the past. You can get private label goods on all types of items including private label beauty, healthcare, and cosmetics. So you have all sort of options when it comes to what to sell.
Good luck and let me know if you come up with something great to sell!