Coilover suggestions?

[Spudboy]

1988 MKIII, Turbo, all stock w/all stock options but 17" wheels/tyres. Original owner, 67K, very clean and top notch mechanical shape.
Getting ready to play street race car builder. Plan on starting with suspension then more power.
I've narrowed suspension down to Tein Flex or Tein RA's. Any experience or suggestions?

This is a 'Toy' and does not need to be a daily driver. May even want to take it to the track someday. (Roadcourse of course)

I also live in the mountains and enjoy going fast up and down...best when running with some other driving enthusiast. I enjoy surprising newer more expensive sports cars and look forward to really embarrassing as many as possible once I stiffen up the suspension and eventually get more power.
(I will leave it a sleeper)