I need to buy a new suspension, and don't have any knowledge about the options available. Does anyone with HKS, Apex'i, Tanabe, or Mazdaspeed setups care to comment? THanks
Alfie

 

All the ones in your post are more of a street/strip coilover. Anything with a spring rate less that 450/350 lbs/in front/rear might still be OK to drive on the street. Shocks come in two variations: compression/rebound adjusted with just one **** or double adjustables were compression can be tuned independently of rebound.
Also, you might want to check with Truechoice or M2. They both carry some nice setups. And will match the shock valving to the spring rates.

Good luck