Can I upgrade some day to get a crisp digital sound as per normal CD by getting the tunner(FM) disconected and a good CD player. Sorry the question got very muddy! Will I still be able to make use of the changer if I get a CD system installed? Thanks in advance!

P.S. What do you think about Pioneer? This will be my first Pioneer system. Are they reliable?

2001 Cavalier
150-175 more kms
per tank of same size
Pioneer 12 CD Changer

SOLD Green 98 Mystique
GS Sport
Zetec ,ATX
885 Fogs mod.
Hi beam mod.
205 15s