Thank you very much for the tips! I would love to add it all at the time we build our home, but I don't think it is going to work out. For starters, the panels are going on our detached garage (for several reasons, one being that the roof will face due south), but the garage will not be completed at the time the house is. Also, due to the sale of our current home and a few other factors, we will be right near the 80% on our mortgage and won't be able to fit the panels in without a second mortgage or PMI.
Our plan is to use the tax credit from our geothermal installation plus some other funds and install the panels in the spring of 2015. Then, in the spring of 2016, we will use the tax credit from our initial solar install to add another large chunk. This will also give us a year in our new home to determine actual energy usage to ensure the system is sized properly.
We are planning to go with micro inverters as you mention. I hadn't thought about the compatibility, but that's a great point. I am somewhat mechanically inclined, and am considering doing the second installation myself after the 'big' things are done with the initial installation. Heck, my dad was a carpenter and he had me putting electrical outlets in when I was 8!
10-4 on the utility agreement. I already have the details for that in hand. It is a 'net usage over 12 months' type of agreement. At the end of every 12 months (starting when your installation goes live), they wipe out any excess you have generated. So, if I install in April and generate extra in April, May and June, that will carry over until I use it. However, if I don't have it used by the end of March the following year, I lose any credits...they do not buy any back from me. That's why I definitely don't want to over produce and would like to stay right around 80-90% to just account for the $20 minimum charge just to have a meter.