As far as protege's aftermarket: There is absolutely no way to match spring rates with rebound/dampening rates seperately, meaning by purchasing struts and springs seperately...For the absolute best handling available JIC's are it...Tein's SS kit is good, but you cannot seperately adjust spring rate from ride height, meaning the more you lower the car, the more the spring rate increase...Look at JIC FLT-2 system like Tein's Flex sytem, but the Tein Flex's are not available for proteges as of now...
Suspension tuning is the hardest, most inconsistent part of vehicle modification...When you add parts to make your engine stronger you increase it's ouput and realize this when it throws you into the seat harder...When you build up your suspension and make it stiffer your car handles better, and you know this how? does it do better over s*** pavement? does it corner harder around different on ramps?...All this s*** aside, your decision can make or break the suspension's geometry...
If you must retain the stock struts for budget issues, don't get anything but Eibach's for springs...They offer the best compromise of ride comfort and handling power, with an decent drop...If you can go with aftermarket struts, you can also look into Tein S-tech springs or H&R's...which are much stiffer than the Eibach's for even better handling...ride will suffer a bit though...
I have never in my life recommended stock strut utilizing coil-over setups like Ground controls or Skunk 2's...they are absolute s*** for the stock struts...I am not trying to get flamed, but the only real benefit these things offer is massive drops...If the drop is kept to a mimimum, the handling will be a little better with only slight ride quality deterioration...slam your car 3"s with the stock struts and handling will suck on anything other than a glass smooth racetrack, and ride quality as well...
You need to find how much of drop you want, what kind of handling power, and what kind of ride quality...Increased spring rates require increased dampening force...Without the dampening force adjustment made by stiffer struts, the car will bounce a little when the struts are new, and within a few thousand miles become exhuasted and bounce uncontrollably..the increased spring rates push the car back to nuetral much harder and faster than the stock springs and the stock struts cannot begin to smooth out the transition...
I purchased Tein S-Tech springs, a fixed spring rate setup, and am still using them with stock struts...The shocks are dead after 5,000miles on PA roads, and bounce is embarrasing (sp?)...The handling was excellent for the first 1000 miles or so, but spring rates that are as stiff as these (the H&Rs are even stiffer) destroy wimpy strut valving very quickly... I will next purchase some Tokico Illuminas to control the rebound...