A Kit is what you pay for and if you pay for it to be built, that's another thing.
If you don't like to perform maintenance or Don't have "Skills" then money doen't matter.
If you drive the car seldom, your attention to "tuning" is less then if was a daily driver. Lack of Performance will be more noticable however, if its really running rough it won't matter how long it has been between drives.
I personally don't have the opportunity of drive the car as much as I'd like too however poor performance is poor performance.
I routinely adjust my valves, adjust my dual carburators and check my iginition/timing and Suspension. Because when I drive the car, I "Drive the Car".
If your are more inclined to the "Hot Rod" type of car, you might consider a "Roadster" Type Body.
What ever you do, you're going in the "Right Direction".
"Keep the Shiney Side Up",
Jack Blake