Inevitably as you lower the vehicle, you sacrifice "some" ride quality. One simple reason is that you are relying on less hardware to do the same job which is a limiting factor. The thicker and shorter springs can't provide the same compression and rebound qualities for starters.
How much you sacrifice depends on what type of shocks you choose, how low you go, whether or not you get the front bumpstops cut correctly, whether you do the free travel mod etc. If you go 3/5 drop - buy Z71 4x4 suburban front bumpstops
The drop is also compounded by thinner rubber sidewall on bigger wheels. Again, less hardware to do the same job. To be honest, I'm not sure you'd even notice ANY difference with a mild drop. Just put your same wheels back on if you bought new ones. That way, you can first gauge the difference in drop. Once you are comfortable you have done everything to retain or improve the original ride quality, put your new wheels on. You'll be happier doing it that way, but that's kinda like saying build your tranny first before you add a supercharger! You probably want the SC first
BOSS