has anyone had experience with custom made Ground Control springs?

I want to use H&R Sports with Neuspeed-Konis, but I don't know what the spring rates are for the H&Rs. I do know that it is the exact drop I want, and it is very street-friendly.

I also want to get the best linear spring setup for auto-x with daily driving in mind.

as for my 2 sway bar choices (Comptech and Eibach), the Eibachs have a solid front sway, while the Comptechs are partly hollow. I think the Eibachs would be a good choice because I would also get a set of adjustable rear sway endlinks so I can get more oversteer for the track, and set it back to normal for safe, predictable street driving. The Comptechs maybe not be as sae and predictable for the street.

Eibach:
23mm solid rear
27mm solid front

Comptech:
22.225mm solid rear
27mm hollow front