David,
I'm using H&R - but I was lucky as I pick them up used.
Your quoted price is not bad - with install it sound pretty good - as they are only charging $ 500.00. My install only cost me $ 700.00 and that was the cheapest quote.
I can provide you with comments but they will not be accurate for the following reason:
1. I have a
MCS which use a SS+ suspension.
2. I have 18" wheels which I had installed before the spring.
My comments:
1. Car corners much better with less lean.
2. Realise that the stock shocks are much softer when you don't have runflats. There's not enough dampering .
3. Good ride height - but my front lip below the spoiler keeps scratching on steep areas.
4. Ride quality is o.k. pretty comfortable.
5. With a full car of people the springs do go down another .75" - 1" in the back.
I have not tried the Eibach - but they were my first choice. Heard some good comments about them.
Eventually i'll go to a coilover system as i'm not too happy with the standard shocks.
Hope this helps.
Cliff