If you set a good pace, probably about 100 hours. That's printing at 60 shirts an hour.
1. Unload/Load - 10 seconds
2. Print/Flash - 20 seconds
3. Print each color - 25 seconds combined
Some could go faster, and some slower. My recommendation, don't be afraid to get quote for someone running an auto. It might save the headache and hassle. It won't tie up your press and I think you might be a happier person in the end.