Best Coil Suspension Conversion Kit?

[Sweep_the_Leg]

I have received the dreaded diagnosis that both front air struts need to be replaced. Rather than continue to throw money (and time and annoyance) at a "feature" that I will never use and could not care less about, I am taking the plunge on a coil conversion.

In looking through all the various threads on this issue, I've seen reference to certain kits or combinations, but I never found a thread dedicated to just reviews of the various options that people have chosen. To my knowledge, for a four-corner conversion these are my choices:

1. Strutmasters kit (with warning light module) - They advertise Eibach springs, but no indication on the brand of shocks. This kit apparently gives you a stock (normal air level) ride height. I also see at the bottom of the description that their four-corner kit only works on 3.0 and 4.4 models, not 4.6is, 4.8is, or 4.4 sport models. Does this have to do with spring height? Or is it something different?

2. American Air Suspension - Looks like the same exact kit as offered by Strutmasters (even the same picture).

3. Suncore Industries - This kit looks different, and there is no indication what brand of springs or struts it includes. Looks like they have just put some Suncore stickers on whatever brand of shocks they are.

4. H&R + Bilstein shocks - H&R's site is showing a sport spring kit for rear suspension only. Anyone used H&R's on a four-corner conversion?

5. B&G springs - Looks like they have a four-corner kit. Any experience in lowering effect and ride quality with these?

Any experience, advice, recommendations related to any of these is appreciated. Are there any other possibilities I haven't listed? I know KW makes the coilover kit, but I don't really care about the adjustability or ability to lower the car to that level. Mainly, I just want to be sure that I won't have to worry about any suspension issues for at least the next 5-6 years. Factory ride quality or slightly harsher, with perhaps some slight lowering, is all I really want.