I'd like to see some more info on this topic myself. I've got a 93 and have also been looking at suspension mods. The list that I've found or heard of are griggs racing, maximum motorsport, kenny brown, steeda, and not sure if you heard of these guys, but Agent47 and JME.
From what limited research and reading I've done I think it all depends on what you're looking for and what platform your aiming at mod'ing. Mind you from the fox to the sn-95 changes to suspension are almost interchangeable. S197 I'm not all that familiar with so can't say. I'm pretty sure some companies are stronger on certain platforms than others.
Rankings in general from what I've gathered in reading the interwebz: (not a factual/statistical thing):
1 - Griggs/MM
2 - KB/Steeda
? - Saleen
? - Agent47
? - jme enterprises
From the hard-core road race crowd I usually hear or see about people using MM stuff due to the quality and price combination. Hard to beat.
However, the hard-core/deep-pockets crowd seem to lean towards the griggs.
Of course I also think your geographical location comes into play as to what you see out on the road more often. Steeda in florida, kennybrown out near his location. One oddity is I usually don't hear about people going out and buying saleen suspension products for track use. I also don't see too many saleens out on track (could have something to do with the collectibility of them). Performance Autosport shop in virginia has pictures of saleens being used on track so I'm sure it's being done by someone. I just don't hear about it all that often. Based on this I'm not sure exactly how they would hold up and compare.
Agent47 is relatively new and not sure where to rank them but the fact that the rookie driver set the track record at infineon raceway in a sn-95 during NASA's American Iron competition leads me to believe they're doing something right. They've got a double a-arm front setup that looks good. (see their website for more details). They currently don't have a front and rear "kit". But their front does warrant consideration.
jme is also relatively new and again not sure where to rank them. they've got a new sla front setup that won the best engineered new product sema 2007. I know they use it on their NASA American Iron car. To what success I'm not sure, but it's being used. Same as Agent47 I don't think they have a rear component so it's not a "kit" per-se.
There are a few other companies, but I honestly haven't heard anything about them so couldn't say. UPR and ground pounder are two that come to mind.
Another topic worth considering is the IRS. I've seen/heard of people swapping them into fox mustangs and swear by them. However I've also heard of people swapping IRS out of a perfectly good terminator in favor of old school tech for road racing. WTF???
Anyhow, if people have used or know of someone that's used any of the components above with success or even failure please post up on how it feels on track and on the street. I would love to read more about real world use instead of just relying on advertising.
Post up yer thoughts!
Thanks,
Gut