Finding floorplans to build

We found a great builder who has been recommended to us for our next home. the problem is deciding on floor plans that we both agree on. He said he will build anything we want but my husband and I just cannot seem to agree on a home plan. I want a two story and he wants a ranch. For some reason he is concerned that we will be old in this house and not be able to make it up stairs. I just turned 30 years old…I think I have some time before my legs give out. We need to make up our minds.