this right here is a very good link that jb provided:
http://farnorthracing.com/autocross_secrets6.html
guy really knows his stuff & the conclusions he comes to is about the same as what I found when I was doing a ton of research on shocks, which is why I built my coilovers starting with a pair of koni yellow dual adjustable touring carts... bilstiens were not an option that I could source correctly for the application so koni's were next best, it's amazing how much garbage there is out there though which is why I've always been very skeptical of a cheap set of coilovers...
here's another link from the same guy:
http://farnorthracing.com/autocross_secrets18.html
man, I wish I could have went with a set of penske's but were talking very high dollar pro stuff there, way more than needed on a street car for sure... can easily wind up spending over $5k to build a set of coilovers based on Penske's & there def a bit overkill...
problem is, no one is going to build a really good set of coilovers for an fx, just never going to be much market for a $3K coilover kit on a car like this, so in the end were pretty much stuck with mediocre at best, & even that might be a little bit of wishful thinking tbh
only way to get a high end set of coilovers on an fx is to custom build them, not something most can do really... hopefully the coilovers your looking at are pretty decent at least...