Market research for amazon affiliate niche and blog

Im looking to set up a blog and an amazon affiliate site.

Look for spreadsheet and a report.

Needs to support adsense aswell.

Competitor Research
market demand
-Analysis of Market Segments
-Category or Niche Opportunities
-Reporting on Keywords and SEO
Product success
-Forecasting

etc

I have a couple of niches that i am interested in. i will need research for each one, along with a conclusion as to what the best niche for both, are best to pursue with.

Im looking for low -med comp, keyword difficulty, can i write 50-100 pages on that niche


Blog Niche

Dividend Investing
Value Investing
Yachting
Sailing
Wines and Whisky
Real Estate Investing
Fine art
luxury mens suits


Amazon Affiliate Site

Organic skincare for men - first can you see if there is a market for men with dry skin, if not, look at all skin types
Luxury Pens - im a big fan of fountain pens, ballpoints, - think of mont blancs etc - is there a micro niche? Is it profitable?Mens formal shoes - fan of oxfords, brogues,


Hope it makes sense.