You are not getting a different coilover because you order G50 over Z/R32. What you are getting is the same coilover with a different combination of tophats, and possiblly lower mounts. Although I'd be surprised if you ordered them and didn't get a 90-93, AKA Z/R32, front lower mount (modification needed or swap the third link for 90-93). The damper is still exactly the same and one is not designed with more weight handling than the other. Personally I would not put K-Sport or D2 (same manufacturer BTW) on my car. I was running JIC Super Lows and loved them (for sale BTW), but for my reincarnation I will be running custom BCs (McPherson front conversion). Dollar for dollar there isn't a better coilover out, but you have to know what to order because there's not a G50 app.
The key to the RUCAs is quality, not design. I ran SPL v2/3, which is a half moom, and would put them up against anything on the market. My new setup is all SPL Titanium series. I use "Z32", which is actually just cross referenced S13 (S14 has different tension and toe rods). Sticking to the "Z32" product line ensures you will get the proper parts throughout (including subframe, differential, knuckle, etc.).