Hi Isaac,
To answer your question: you should have different landing pages, and ideally different sites that cater to each of your specific target markets. Think of it this way...when you do your offline and online (but offsite) marketing, you'll presumably using different tactics to drive each different target market to your site(s)....when you tell them to go to a specific site, they'll be expecting to see something relevant to their needs/problems instantly (the headline).
It is much more effective therefore to send each target market to a relevant site than a general massive site where it's not clear what's there for them, what's not and what their specific choices are.
I notice you're using wordpress for your blog - have you thought about using wordpress to build the site and integrating your blog right into it so you're not sending people off to different places?
The key to web (and blog) design is to design each page around getting the visitor to do one specific thing - don't give them too many choices (maximum 3), otherwise the chances are they'll just click off.
Whilst this may sound harsh I do think it'll help you in the long run...I'd totally overhaul the design of your site - separate it into individual ones for each of your target markets - or at least have very seperate sections of the site, perhaps even sub-domains (and while you're at it, you can use more keyword-specific domain names to improve SEO). You can then either integrate the blog into one of them or run the blog of your wilkinspower.com domain and use it to link and tie everything that you do together in one place.
And when it comes to images....use relevant images that enhance the copy. Don't just use images for the sake of them and have an inane picture of a green apple or something like that!!!
Hope that helps...