I would personally so both. Affiliate marketing is about testing and discovering which method proves more effective and more profitable. However, if you're busy a blog might take more of your time in terms of maintance. However if time was not an issue i would do both compare and then compare results and continue with the successful method
I'd do (have done) both.
Yes Google loves blogs - but to a point. The nature of content for both tends to be different. Blogs tend to be (should be?) commentary to a degree. The home page tends to change reflecting recent posts. Website content tends to be more static, tends to have a different structure.
Navigation for websites can be easier - content isn't arranged by labels or by time. For users, websites are still pretty easy to navigate - yes you can do this with a blog but blogs tend to be blogs and websites still tend to be websites.
I dont think Blogs can be seen as a replacement for websites. Both blogs and websites respond to SEO and they both have their own purpose or roles depending on the job!
My opinion is that it doesnt matter if you have a blog or website as long as you keep fresh and unique content and do good SEO job.
Just for anyone interested, I went for a mix of a website and blog - and made first affiliate commission today after 5 months.
I'd say do both. Firstly I'd do your website as a product site with tonnes of info and end user benefits about the product. You could include an ecommerce if that works but definitely have a form to collect registration details. Then secondly I'd have a blog to drive traffic to the product site, you can use the blog to show off your expertise or experience in the market by providing news and information about the said market.
Not sure why you are not considering starting a website AND a blog. It's what a lot of us do and works well for backlinks and traffic
If it was a basic content site then would go with a blog such as wordpress
Products to sell then would use Magento
For community sites - Joomla
...all depends on the customer and what they are looking for