Need guidance with SERPS and rankings(Keyword/Comp. Research)

Hi I'm doing keyword research for products to review for Amazon. It was suggested by a marketer that I'm in contact with not to worry about traffic to the home page but traffic to 'product name + review'.

What's happening in the SERPS mostly is the brand name is ranking high. Also there is other retailers in the SERPS. Competition wise the pages aren't well optimized, have low PR and very few back links. In a few cases the brand name isn't ranking however other retailers are ranking with not well optimized pages, low PR and hardly any back links. Also these product names have exact match search volumes of 100-200/ local month.

Question in the above.... Is it possible to out rank the brand name that isn't optimized well, has low PR and hardly any back links? And can a retailer be outranked?

Another scenario when I'm doing keyword research is checking out what the Google Keyword tool provides in regards to the generic keyword + review/best/top/cheap etc. When I drill down into let's say XYZ XYZ XYZ reviews deeper with GAKT it doesn't provide product names. However in this case the SERPS are coming with non retailers in more than a few cases. What I see in a lot of cases maybe an Amazon page that isn't optimized, 0 PR, no back links.

If I'm wanting to do reviews of 'product name + review' then the first scenario is providing me with specific product name. However like I'm concerned about the competition.

When I go more generic like Generic Keyword Generic KW reviews let's say that GAKT provides me I'm not getting product names in most cases.

From what I've learned from the marketer I'm in touch with is traffic to the product + review page on my site and on the SERPS.

I'm sort of at a road block. Can anyone offer any guidance and/or suggestions.