Best Wordpress Amazon Affiliate software?

I want to get started making Amazon affiliate sites. After doing a bit of research it seems like there are a fair amount of options out there, but there are also a lot of bad reviews, and it's hard to know which ones actually work. Ideally, I'd like a plugin that I can search for Amazon items with, and then auto-post said items to the site. I'd also like a good easily customizable theme. I am willing to pay for these, but I don't want to waste time and money experimenting with random systems. Any advice on the best options?

I like amazon link. It's free, versatile and well supported and has the edge over amazon product in post.

Havent tried any paid options so can't comment on those.