Hi,
First of all, based on the informative manner in which you phrased your question, you seem very intelligent and business/internet savvy - so either way, I'm sure you'll do great.
Answer: I would go for both. Why? Because they are not exclusive to each other. Some people will just want to read about a specific subject/issue/solution within the field, and others will want to read the entire e-book. Also, some people like to have a book layout, versus others who prefer reading short posts. The online concern with an e-book is the re-publishing of the content by a third party - but if you release the eBook only after you publish most of the content on your website, this won't be a problem because Google recognizes who published the original content first.
If the above us not an option because of the specific subject you're covering, then I would go with the online resource option (and not the e-book). The eBook is a once off profit model, whereas you could probably sell numerous products/services on the website (I would of course need to see all the numbers to give you a 100% answer).
p.s.: if the business has a lot of potential (backed by numbers), I would be willing to consider a small investment (if this interests you).
I've successfully helped over 300 entrepreneurs, and am happy to help you as well.
Best of luck