Choosing Quality Niches vs Passion Niches

I'm going go against the advise given here and allow myself to choose a niche that I'm not so jazzed about. I like the idea of leveraging Amazon and doing reviews for products listed on the largest marketplace in the world. AND, I like the idea of qualifying my affiliate products using metrics such as price point and number of existing reviews.

It may be the case that I can find some well qualified products in my true-passion-niche (race car driving). But, if I can't, then I don't want to box myself into a mindset that doesn't scale well in terms of financial return.

I do like business for the sake of business and scaling an affiliate marketing business based on ROI and pure business metrics.

So, here's the process I've got so far:

1. Find qualifying products via Amazon
   1. Attractive price point
   2. Enough reviews to (1) establish online engagement with the buyers in that market, and (2) generate quality authentic reviews.
2. Google keyword research
3. Site research and planning
   1. Site organization
   2. Content/ Keyword/ Article Map
4. Site Construction
   1. Research products
   2. Write articles
5. Optimization
   1. Split testing
6. Repeat 2 - 5 within the same site
7. Repeat 1 - 6 to build a new site.

I guess Iike processes. Sometimes I think that this is actually a sticking point. Sometime it is analysis paralysis. But most of the time, it's not anxiety that's guiding my brainstorming/ planning. It's the honest to goodness fun factor of creating a new plan and dreaming.