Completely New to CPA - Confused...

I have a few questions which I would love for you guys to answer, as I'm quite confused at the moment.

I'm thinking of solely using organic traffic ( to start off with, anyway.)

Say I'm looking for users to type in their email address or post code, would you suggest building a

1. 1 page website promoting 1 offer

2. A multiple page website promoting the same offer on every page

3. A multiple page website promoting a different offer on each page (same niche)

4. A multiple page website promoting 1 offer on a single page, but the other pages consist of helpful content about the product/problem in question and include a banner and contextual links to the CPA offer

- If I go for option 4, which page should I drive traffic to?

I'm also somewhat confused about which keywords to target. Targeting something like "The best acne products" sounds like it will convert, but the competition will be fierce. Same applies if I'm targeting something like "Product free trial.".

But if I'm targeting lower competition terms (even if the following aren't, say that they are for the sake of this example) such as "acne types" and "causes of acne," then...

- How would you presell the offer if you're not going down the landing page route, but are instead relying on contextual links or a banner on the bottom or side of the page?

Acne probably wasn't a good example, as most people researching acne probably will be paying attention to these offers whatever it is they type in. But I think you get the point I'm trying to get at.

Thanks