Sometimes simpler is better
>>I have begun looking into options such as... ductwork to transfer heat from upstairs
>>back downstairs using some sort of duct fan solution.
This is an idea which is so simple and low energy, that I had wondered why it's never talked about. Could it be because it's the antithesis of a 5-figure sale for new HVAC and ductwork? Is there really a legitimate reason why the central fan is looked upon as the only tool to do ventilation? I'm not trying to be too hard on the industry, I know not everyone is always trying to replace a whole system, I know there are ERVs and the like for ventilation. But feel the need to ask these questions to communicate an idea which has never (to my knowledge) been discussed in this HVAC forum.
>>The only reason I have come to this BB is to educate myself as a DIY'er that would
>>rather pay someone else to do the job but cannot find anyone that is capable or that I can trust.
I know exactly how you feel, AB. My own experience has been frustrating but it's very hard to find an HVAC guy who is motivated to do all the things that need doing. I suspect part of the problem is that Building Science spreads over several traditional trades, and people experienced in one trade are reluctant to try their hand at something that involves another trade. And ideally you would like to have a highly educated guy (Lstiburek?) designing things and there aren't too many like him. In the meantime one can feel pressured to be a reluctant DIY-er. In my opinion the board is poorer for not recognizing this different DIY motivation -- it's not really *trying* to pull any business away from HVAC pros, it's motivation is primarily to get a job done. A job that pros usually don't want.
Best of luck -- P.Student