If I wanted to see some of Umbria and some of Tuscany, I would stay near Arezzo in an agriturismo or rent a house or apartment in that area. You would be close to the autostrada (A1) that goes to Florence and to Rome, close to train lines, close to Perugia, Assisi, Chiusi, Pienza, Montepulciano, Siena. I would not miss Assisi.

Lisa in Chicago