Homesteading/rural living outside of San Miguel De Allende?

Hi all, my family (me, hubs, 2 small kids) WERE planning on buying land in the high desert of Arizona, building a straw bale home, and starting a permaculture garden.  Once that is set up nicely, we planned on travelling for a few months out of the year to Mexico.  Now that we're learning and getting more excited about Mexico, we are thinking of making Mexico our home base, and instead travelling home to the states a few months a year.  A switcheroo!

If we choose the expat route, we are drawn to San Miguel de Allende and other mountain towns with beautiful weather.  However, we're hoping to buy or rent a place on the outskirts, more in the countryside so we can pursue our permaculture projects.  We had our hearts set on building our own straw bale home, but would be ok buying or renting an adobe home or other sustainable (eco-friendly) home.  We're hoping for acreage- at least 3-5 acres, if possible.

Can you guys tell me anything about the surrounding countryside of San Miguel De Allende?  About buying land there or renting ecofriendly home with acreage?  About building a home in the area and the red tape?  Any insight is appreciated!  Also, is it doable and safe to bike into town from the countryside?  I know it's very hilly.   

Thank you so much.