Flex alone?

Hello, Love what we've seen so far about the i-house. I have two questions. In going to the "build my house" tab I couldn't find a way to select only the flex. Can you buy it separately? We would eventually like to have a couple of guest residences on our land (we were planning cabins...but these caught our eye). We would love to use the flex portion alone for this if possible. Second question. What is currently the nearest place we can see one in person to either of these two zips? 76063 or 74037? Thank you!