I would have one partner create a separate page/contact form specifically for the advertiser – so only people who see that contact form are people who were referred to by the advertiser. The advertiser would use that page as their outbound link. I know you can track outbound clicks in Google Analytics events and Contact Form conversions (usually through most contact form plugins) but that is the best way I think. Never done it, but this is how I see most affiliate programs like that work.
2. Of course, nearly all my readers are using WP so I’m biased. But even so, most successful affiliates use WordPress. There are less restrictions in terms of hosting (site speed), design customizations, plugins, cloaking affiliate links, lots of things. I would setup a free wordpress.com site just so you can play with the dashboard and see how you like it. Who knows, you might find a theme you really like (eg. StudioPress) and want to make the transition. I would at least test it out…it’s better to make the transition earlier than later.
There are lots of Amazon affiliates in this space, mostly because it’s a strong hobby (i.e. passion) niche with tons of products. Which is good, since tons of these big stores are very general in nature, making it possible for big outdoors sites to possibly even pick one or two stores to recommend (this, in turn, might have other advantages, too, like negotiating better rates with those brands).
The amount of money you can make can depend greatly of you budget. If you have a small budget and you don´t have a lot of money, then you have to start with free marketing methods like article writing, blogging, forum marketing and such. It takes a lot more effort ant time to have success with these methods. But they are very effective if you keep writing articles and participate in forums. You can make $100 a day within just a few months just with article marketing.