All of the HOK PBC's will look different depending on the sealer or base used underneath. Not as much as a real transparent like candy per say, but the sealer or base will affect the brightness of the PBC. You can of course spray your parts off the car, as long as you use the same gun settings, air pressure, and out of the same mixed batch. I normally take all my quarts, and mix them together in a empty gallon pail as soon as I get my paint in case there is any variation from the factory. The PBC's will spray about like a metallic base, or easier in a lot of ways. I would use a white sealer under it though. Your color will be much brighter, and it will stop problems with your primer if there were to be any. I dont use a sealer with every job, but it's good insurance.
This is one a did a while back with a GM solid orange, and a small amount of Kustom Shop dry pearl in the first two coats of clear. The client wanted Tangelo Pearl, but didnt want to spend the cash on paint, so I came up with something close, that would be in his range. Do some shopping, because there are a lot of options.