I have two sets of coilovers for sale. A set of used Tein and a set of slightly used HKS. I live in LA (Pasadena) and my car was used as the final test vehicle for both sets.
The HKS set has two weeks on them, actually I think less than 14 days and 500 miles. They are Hipermax III w/ adjustable camber plates up front [aka pillow ball]. The HKS website has a list price of $2,445 ( HKS USA Hipermax III ), but you can find them much lower online such as:
$2200 + shipping
HKS Hipermax III Coilovers (Subaru WRX 2008) - Modern Automotive Performance
$2,095 + $60shipping
Doesn't look like these have the camber plates
HKS HIPERMAX III COILOVER 08 09 SUBARU IMPREZA WRX - eBay (item 200456324392 end time Mar-25-11 22:17:35 PDT)
$2,385 free shipping
Selling these [HKS] for $950 shipped. Or $900 pick up.
The Tein's have about 18 months and 20k mi on them. If you check the Tein website, the pictures are of MY ACTUAL CAR. They are adjustable, but do not have pillow balls.
SUBARU IMPREZA WRX 5Dr
These [Tein] are $550 shipped, or $500 pick up.
** Tein's are SOLD **
I live in the Pasadena area. Sold the car a while ago. Never raced, autocrossed, off-roaded. As you know, the stock suspension is very floaty/squishy/soft. IMO the stock suspension rides softer than a new Camary. Either of these upgrades change the car's personality 100%. It's like a night and day difference.
Check part numbers (or here in the forum), but the guy who bought the Tein's said they fit his 4 door.
Shoot me an email at firstname.lastname@example.org or you can call/text me at 310.254.8412.