You don't have to create anything to start planning out your URL structure. Lots of times when building something I think about the keywords and then just start laying out the URLs that I think will suport those keywords from a search and overall usability perspective. I'll do this even before I start mocking things up.
From your design you could put all mowers by one company on the same page and then have tabs to separate the content. Implement the tabs in javascript so that they just enhance some good solid HTML lists or divs. That would create one page for each mower brand. Are you hoping to SEO well for "mowers" or "toro mowers"? Perhaps you are already planning on doing this?
In regards to the anchor text, can you just link to "Toro Mowers" and then have people click the tab they want. Othewise perhaps you could do something link "Toro Mowers - Home", "Toro Mowers - Commercial". At least that gets the keywords at the front of the anchor text.
The structure of your site will be important for SEO but start by finding the list of keywords to target. Consider keyword competition and search volume when making the list. Come up with one page for each of those keywords. Then try to come up with an overall URL structure where you can SEO all those pages well. Finally, don't worry about SEO on each and every page you create. You are going to have some pages that add to the overall experience of your site that might not target keywords.
You are smart to think about creating only the pages that you have good content for. I wouldn't force myself to create any other pages.