I am looking into getting coilovers as recommended by you. When shopping around for coilover options I refered to this post but I realized that the spring sizing of 5k, 6k, and 7k is not clear to me. Is the sizing based off kg/mm? As in 5 kg/mm and 6 kg/mm springs are recommended as the ideal setup.
I reviewed another post stating that k sport, BC, and D2 are similair at the $1,000 price point. Higher cost coilovers allow for more customization. Is this an accurate assessment? I am currently looking to purchase D2 coilovers.
Correct. 5K, 6K etc refers to spring rate.
I wouldn't copy my setup, I'd say a 6K front and 7K rear is good for most folks. If you get into competition, you can play with it from there since there will be no "ideal" setup for everyone.
To answer your question on cost...kind of. You can get better springs on the BCs at a higher cost but there is no more or less customization for that cost. Also, it's not about customization but rather adjustability.
Generally, when you jump up into the $2,000 price range of coil overs (and higher) you're looking at shocks that are either custom valved to YOUR spring rate and/or shocks that have independent adjustment of compression and rebound. Simple answer is, if you're unsure about what those things mean, stick with the $1,000 shocks because having that adjustability will probably cause handling problems if you don't know how to adjust them properly. The less expensive shocks have one adjustment for dampening and it's softer or harder.
I don't want to have that come off as sounding condescending. I have $1,000 BCs with just the single adjustment because while I understand what it means to adjust rebound and compression...the when and why is still a little fuzzy and I wasn't comfortable having the independent adjustment. Soft and firm work fine for me right now. LOL