You should ideally buy springs and shocks as a matched set in a kit. When you get sports springs and use stock shocks, the shocks will tend to wear prematurely. They are designed to be a blend of comfortable ride and safe handling. By using shorter springs, the shocks are now overloaded. Getting a kit will mean that the shocks are matched to the length of springs.........HOWEVER, If you are planning on lowering your car 2" or less and you use a spring like Eibach, Neuspeed Sport, H&R Sport or either Tein S-tech, H-tech, You should be fine for quite a while.
These Springs are generally promoted/made for just this situation..........unless you are close or past an OEM shock's life expectancy of 65K miles

If you lower a car on stock shocks/struts, You have a safe resting area of about 1.75"-2" in the shock, This is called the "Sweet Zone" (no, I didn't make that up).

The definition of Sweet Zone: The inside top area of the shock where the piston sits when not being compressed or in action.
This area is stronger then rest of the shocks inner wall and is made for the piston to sit in when not being compressed.
If you lower the car more then 2", When not in action.....The piston will sit out of the sweet spot and quickly weaken the bottom of the shocks inner wall, You will also be adding a lot of pressure to the piston and ring at all times which will put to much premature wear on the compression components and stretch the inner wall causing blow by of the gas/hydraulic oil.
If you use cheap springs (even under a 2" drop) the spring is not engineered correctly and does not have enough resistance to keep the shock from bottoming out.
If you use Name Brand Springs and plan on going over a 2" drop on stock shocks, Not only are you out of the Sweet Zone, But You also have a much better chance of bottoming out.
The spring is allowing the shock piston to compress all the way and after the rod and piston of the shock hit bottom a couple times....The shock is done and looses all pressure.

As an example, On my '04 Accord Sedan, I have been for the past 8K miles using a set of Tein S-tech springs (1.75" drop) on a set of HFP = Honda Factory Performance shocks.
The Drop is perfect and the Ride Quality is very close to factory comfort with just a smidgen of that stiff performance feel.
I highly recommend Tein springs !!!!
On another note, I was using H&R Race springs (2.5" drop) on my Jetta with stock shocks/struts for under 4K miles, My rear shocks died very fast and I had to upgrade to Koni Yellows.
My Tires got some uneven wear and now I have a horrible case of road noise in the rear.

So you really have three choices here,
1) Go with a Brand Named Spring w/ minimal drop and stick it out with your OEM shocks.
2) Take that chance, Slam It and end up replacing tires and shocks/struts within 4K-8K miles down the road.
3) Keep it stock ride height for now and save up to go all out on a shock/spring drop kit.....Then Slam it!!

Best of luck with your decision.
If you need any more support or Labor work done, Please feel free to PM me and we'll get you hooked up the right way.

-Jeff