Make My Garage Door Taller

It has the old style carriage doors.
Make my garage door taller. I have a detached two car garage that is getting up there in years. I live in northern new jersey. I need to cut the opening to the garage 6 taller. That is the easy project as the building is plenty tall for this.
The wife wants to replace the two with one 16 overhead garage door. The door track should be easy as well. That made my door height two inches taller. I would also go a few feet taller this would allow for a taller mudroom whose roof would actually clear the edges of my back door.
I removed some siding and and re did the trim on the top of the door and then recovered every thing with aluminum and installed new rubber garage door sill around the opening. I had a 2x6 on the flat under the header so i just removed that and cut a half inch off the header. This would be closer to 10 000. The garage is a total of 24 wide by 24 deep.
The replacement garage door should be one that hangs above the front of the garage and lowers down from the outside so it doesn t affect the height of the garage. We had a few contractors in to give us. The garage also needs a new floor and a new roof.