SEO question for my future local business site

Hello folks,

I can use some inspiration on how to set up my business strategy online (it's not an online business, but I will need to attract customers by using a good site).

Basically I will soon register my future company name. It will serve as the base for my business.

I am fortunate that my area of expertise can consist of many small sections, and there a lots of Exact Domein Names available so I believe that this is an extra opporunity to create my own network.

The question is how I should do this the best, I already have a couple ideas in mind:

1. I set up a Wordpress Multisite on subdomains, but I link the Exact Domein Names to the smaller sites (example: Wordpress will be installed on animals.com, a section will be created as fish.animals.com but a domain name like fish.com will link to the subdomein). I basically create small niche sites.
   
2. I maintain all the content on my business site, but register the exact domein names and 301-redirect them to a page on the site (example: fish.com will point to animals.com/fish)
   
3. I maintain all the content on my business site, but register the exact domein names and use an invisible frame to link them to a page on the site (example: fish.com will actually be animals.com/fish); I've seen this technique on sites with static pages, but I wonder how it can be done best with a Wordpress site (or could the 'duplicate content issue' be solved by using a rel=canonical attribute) ?
   
4. I forget about the exact domein names and try to optimize my site for all my desired keywords the best I can.
   
5. other?

I think the Exact Domein Names are a huge opportunity. Some of them have almost no competition so I think it's a good idea to use them. In fact: I already made a website with low competition, which turned into a huge success because it ranked 1st very fast and with the increase of visitors, it also ended up with better results for other pages on the site.

The most important part is that my visitors will be converted into clients, so I will have to make sure that every domain feels like it's part of the bigger business site (so I will be using 1 template for all websites and try to make sure my navigation covers the same for all sites).

The plan for the business site itself: it will be primarily used to optimise for local visitors and to identify myself and my services.

Do any of the above techniques make sense? What do you think I should use best? I'm a little worried about duplicate content and since I haven't used these techniques before (so far I've only built single websites without network) I can't really predict the impact.

Thanks in advance for any response. I hope everything is explained clear, if not I can always provide more info.