BD, before you go too far with your plans, you ought to give serious thought to having your house be much better than "to code." There is a wealth of information available on building houses in the "superinsulated" realm. One very good source on doing this is here:
http://www.greenbuildingadvisor.com/...tty-good-house. Other good articles may be found there on GBA and on
www.buildingscience.com.
Basically, for this region, you want your house to have better-than-code insulation levels and great windows (eg. triple-pane) and be exceedingly tight with mechanical ventilation. Extra cost to achieve this usually is on the order of 5%. But for a mortgaged house the extra cost can be less than the yearly-averaged monthly heating savings, so that, strangely, it can be less expensive to build the more expensive house. Even without the long-term operating cost savings, a home built to be much better than code will be much more comfortable inside, winter and summer, and be more durable in the long run.
But to get there you need to do a lot of serious reading to understand the principles. It isn't rocket science, but it is building science. Finding a builder willing to do things differently from the way he always has built houses may be a problem. Many don't yet understand all the myriad things that must be done before and during framing and don't really want "different." If a prospective builder tells you not to tell him how to build, that he's been building houses for thirty years, find another builder. You don't want a house built the way it was done thirty years ago. It's your house, you get to call the shots, not the builder.
OK, off the soap box.