175-225. There'll be 3 different 12" springs to choose from in that range. I am using, (and have used) #175's on the front of my last car, and the current one I'm putting together. They look like they're almost collapsed when there's weight on them, but there will be about a little less than 1/4" or so between each coil. When you add that up between all of the coils in question, there should be about 2-2.5 inches of compression left in the spring at ride height.
A 175# spring is obviously the softest spring you can use, and the ride will be commensurately softer as well. There are guys out there that are using a much heavier rated spring that use the car in autocross/road racing. So be sure you know what you want performance-wise from the spring.
It's all in what you are looking for in the end.
In my case, "the end" I was was more concerned about was the one that sits in the seat.
I've had s stiff/handling suspension in this car for the past 2+years and want to focus on optimizing for the strip. Still drive the car on the street also but don't care about carving corners anymore.