I have mine registared as a 1965 Cobra Replica. I also got the SP plates because most of my driving is on the track. This is nice because it only has one plate as opposed to having two plates ( front and rear) for none-SP applications. Read the restrictions of use for SP plate and see if it applies to your use.
If you do not have a VIN for your kit DMV will assign one. You will likely need a vehicle inspection if you do not have a VIN. No big deal if your car is put together well.
That particular DMV office has coped an attiude with you and or your car. I would not go back to that one. I recommend finding another is a similar small town. Stay out of the bigger city DMV's. I went to the Dallas DMV. They were friendly and helpful and I was done in no time.
Which by the way was very fortunate for me as the weather was becoming very bad and I need to get my little queening home and under cover!