So I've been doing more research and after reading a very informative post on another site (Post #8): Who's Rocking KW V1's? Or V3's?
Do you see yourself competing at all with this car in handling contests, either Autocross or Road Course work? If so, then save yourself the money now and get the adjustable units. I will say this, KW makes an excellent product from what I've read, but my gripe with the Variant 3's (and 1's as well) is that they use stock sized front springs, NOT coilover springs. They also don't come with camber plates. They are also a steel twin tube damper instead of an aluminum monotube. For the price, if you are looking for performance and adjustment, you can't beat a quality monotube with proper coilover springs and the lighter weight helps keep unsprung weight down which is important to both ride and road holding capabilities. Monotubes dissipate heat better (afterall, the purpose of your dampers is to turn excess spring energy into heat to slow the oscillation of the spring) than twin tubes do and offer far better suspension control. When valved right they will ride better too. That said, the KW's are expensive to revalve and rebuild because parts either have to come from Europe to rebuild them/revalve them, or because the entire coilover system has to be sent overseas. KW USA seems to be doing better, but in the popular race series where they where doing well (Grand Am/Continental Tire Sports Car Challenge) they have pretty much been beaten out by other competitors that offer better stateside services. KW also uses progressive rear springs with waaaaay tooo much rear spring rate for these cars. The working rates start above 200 and end above 400 lbs/in at extreme suspension travel. The fronts are also 450 which is getting to the edge of tolerable spring rate for daily driving on these cars. One such company beating out KW in racing series is AST who produces monotube coilovers for these cars at a very reasonable price, with optional valving for street/track use that wont kill you (Digressive Pistons). They are worth checking out if you NEED coilovers.
On to the Coilovers, it seems that most people that come from other cars go straight to coilovers before considering a set of lowering springs and good dampers. Unless you really NEED coilovers for competition use or for shows or what have you, you are really better off with a good set of lowering springs and good dampers. Coilovers that offer no adjustments appeal to one crowd, the show crowd and while there is nothing wrong with that, it's a lot of cash to drop on a quality set (as you are finding out ) to show people or say "Yeah, I've got coilovers".
Right now there are three total coilover kits that are true coilovers for these cars. Griggs Racing, Cortex Racing and some small company that makes light green coilovers with Swift Springs all make a proper rear coilover kit. Otherwise the geometry suspension wise is identical to what you already have, a proper MacPhearson strut front set up with the spring over the strut, and springs inboard of the shocks in the rear but with adjustable spring perches for the rest of the coilover kits. Nothing wrong with that set up, it just defeats the purpose of having "coilovers" for the better motion ratio when the rear motion ratio still sucks.
With that said, lowering springs + good dampers (Koni Sports or Koni STR.T's or custom valved Bilstien HD's) will suffice for 99% of the population who don't need ride height adjustment or extreme control over the damper properties. Yes, the Koni's are twin tube dampers, they are some of the BEST twin tube dampers in the world. The Bilstiens are great, but their non-adjustable nature is a non-starter for someone looking for competition shocks.
Remember, Coilovers don't have to kick your *** in ride quality to be good. A proper set up will be firmer than stock but will not be jarring over rough roads with sane spring rates for a street car.
All that said, the KW's are still great bits of kit, but really overkill for the majority of drivers on the road. I would NEVER buy a non-adjustable coilover kit that I couldn't tune for MY needs. I see myself adjusting ride height a lot less than the damping properties...
If you are still interested in coilovers, check out AST. Vorshlag is one of the largest AST distributors and Terry Fair is an outstanding individual who can help you decide which kit is best for you. Expect to pay, with springs and camber plates the AST 4100 series (rebound adjustable ONLY and the "base" model) runs about $2600 but it is a proper Monotube, aluminum bodied, rebuildable and revalvable, digressive piston coilover kit with sane spring rates (350F/175R) for a daily driver. Terry Fair's wife daily drove for thousands of miles on a set of 4100 series coilovers without complaint. The Vorshlag camber plates will get you to -4º of camber down to stock levels at pretty much all ride heights.
I'm not associated with AST at all, they just offer the best value to performance ratio of any coilover kit currently on the market.
It seems like an AST 4150 Coilovers kit will be more suited to my needs and I will get the sway bars after the coilovers, perhaps a camber kit also if I want it lower, but that decision is up in the air.
Now I was also looking at just getting a set up like this: 2011-2014 Mustang Steeda Sport Suspension Package 555-2352
However, since I can't adjust the height with a package like that I'm pretty much stuck with it, so unless I meet someone at a car show who has something similar and they take me for a ride so I can get a feel for it, I'm not sure if I want to go that route.
Does anyone with some suspension mod experience have any feedback? Am I on the right track or am I missing something?