if you are serious about doing road track stuff do some events in your DD and learn how to drive first, in a rental car if you gotta. "you will never drive a fast car fast till you drive a slow car fast" find a miata that already has tons of parts on it. do some research and do what needs to happen to make it reliable on the track.
the car is so much lighter then most cars the conversion from a normal car to a set up miata can be difficult for a new track driver. dont spend a much of money on brakes , let em fade a bit and use that to force yourself to carry more speed in the corners.

my feeling is that if you are set on a car that will do such and such time 1/4 mile then that is still your priority. that is fine but it is not a road track mindset. if you want a fast turbo miata for the road track then I would not worry about times at all. a good set up road track car is not going to trap as well as the same car set up for drag. I'm not saying you cant do both. I ve only been to the drag strip with my audi a4 and it was boring for me. I managed a 12.8 and a 60' at 1.6 but that is with a all wheel drive launch. after a 1/8 mile I was done , boring. decent car on a road track tho.

and what did it take to get there? :-)