I would strongly encourage you to think less about systems and more about performance goals. * How much energy use? * How much carbon do you want to burn?

I would strongly encourage you to think less about systems and more about performance goals. * How much energy use? * How much carbon do you want to burn? * How much money do you want to spend year over year? * What kind of indoor air quality do you want to achieve? * What is your comfort zone temperature wise? Then design your system around that. This also encourages thinking about how these goals interact with site conditions: glazing, solar orientation, climate, etc. I don't know the scope of your project but consider getting a mechanical plan drawn up. Most residential projects don't have them and in my opinion (I've been building since 1999) it's a lost opportunity for a better, more efficient installation.