I'm dropping the rear to replace bushings, while there I'm going to replace springs and shocks, I've decided to NOT go with CATS (yes I'll be replacing fronts also), I can't justify the cost so I'll 'pull the plug'. I feel a bit stiffer spring will offset the need for cats.
Question, Who's used what and your experience: I've looked at Arden/Amadesh and Mina

 

I have adamesh springs but they are not noticeably firmer than the originals.

I had replaced the fronts because the old springs were starting to sag. The lowering spring is actually higher than before. The rears I did just to bring the rear down a bit and moreover the look.

No problems at all and part of the reason for choosing adamesh was that they are one of the smaller height changes.