It is an interesting dilemma. I have considered this as well. One consideration is they both will enhance each other in someway with the linking process, the marketplace, and of course the market. Possibly it is the target market and the marketing plan that is being given scrutiny?
If a new HP account is set-up as complimentary to the website the advantage is the marketing concept and advantages offered by HP. One would have to evaluate those. Both will be influenced by SEO practices of course. Some SEO practices are built into HP with the category selections. One advantage is creating Brand Recognition with both entities as a singular unit contrast two entities.
That offers the opportunity too of a blog to compliment that same Brand Recognition. A little thought for the 'titles' or names with any power of keywords will play with that process. I would think tying all three entities or more together with a singular purpose and that Brand Recognition may be worth consideration. The purpose for each entity as a tool for marketing the product - information, has vast opportunities that may be capitalized upon such as . . .
Commentary specific - broad stroke of the information illustrated with generalities with opinions and viewpoints
Essay specific - narrower stroke of the information illustrated with specifics and acuity
Choice specific - types and application of usage - home, business, locality / municipality, region, state, national, worldwide and/or history and/or current thought and/or age group - life position - groupings and/or geographically and/or ???
Organization specific - professional organizations and there positions and grass root organizations and there positions
and more . . .
I have been pondering those with a couple ideas for a bit and byte now. The fact you have decided upon the subject contrasting myself is a great plus :) I guess another consideration is passion.