Paint advice

[aonemarine]

One gallon is 1.5 gallons sprayable in laquer. I can shoot a full sized car , jambs, inside trunk, and under hood with 5 qts non reduced. I would think 5 qts un reduced for a roadster is plenty. So 2 gallons would give you enough to make all kinds of mistakes.
Be sure to use a good thinner with your paint, laquer thinner for clean up is not the same.
I havent sprayed laquer in 20 years plus but have 2 gallons of black laquer set aside for mine when the time comes. I understand why you want to use it.

 

[aonemarine]

Look at the evercoat superbuild 4:1 primer....just started using it. easy to block and is very high build. Pretty decent stuff for the money.

 

[J Franklin]

I used to buy 3 qts in a gallon can (RM) and add a qt. of reducer and it sprayed great with full flow-out. I could do the exterior of any full-size car provided no real mistakes. I once did my 66 Mustang coupe with 2 qts. but forgot the headlight rims that were off the car until I was about out of paint. I washed the can with some reducer and added that and put it in my touchup gun to get the last drop and saved the job! I'm glad it was not a metallic paint.