Chances are if your struts are original, they may not be up to the task of handling the higher spring rates.
If you're just putting lowering springs on it then new oem struts should work fine. Of course if you're looking for a significant increase in
handling then upgrading the struts as well is recommended.
If you're you're looking for something smooth, get a matched spring / strut set. They give you some drop, ride pretty good, they're matched so you know the spring rates won't break your back, and they're usually affordable.
Coil overs .. Depends on the kind. Full coil overs give a lot of drop, but can be rough (if you drive on poor roads I REALLY suggest you stay away, UNLESS handling is what you are looking for). The other common problem with coil overs is that people are tempted to drop it too far, too soon. If you drop it too far, your camber will be so negative you'll eat tires like it's cool, it's worse if you have performance tires as they are much softer. The camber should be corrected when dropping significantly, but sooooo many people neglect it and blame their "crappy" tires for not lasting more than 2 months lol.
Coil over kits are -ok- If you put them on a decent set of struts. Nearly all kits take some modification of the strut to get the drop you want, but it isn't too hard.
I've had every freaking imaginable combination you can think of.. My suggestion: A reputable (no ebay crap) coil over kit on adjustable dampening struts. imo
