I like to search keyword for Amazon affiliate. When I start searching, i do research like a crazy. So, I think i can search for you too. I'll provide matrix through google keywordrevealer. I like the keywords which one's search volume is around 1500/ months and keyword difficulty is less than 30. Keyword pattern would be best + keyword. I will provide you the matrix of other patterns like keyword + review and cheap + keyword for absolutely free. You have to provide me me the CATEGORY which you like most. I think, I can meet your requirements.