You can use a factory late model unit with cd player as a plug and play alternative.
I used one from a 93 caddy, I think...... it's been a long time but an internet search should get you the info you need....
I do still, however, have that 80's shitty, no bass, tinny sounding system because I only changed the head. I haven't yet done any other system upgrades.
There are several folks out there that will upgrade your stock unit with an RCA jack that will let you plug in an iPod or other type MP3 player. The same can be done with a comparable unit with a CD player in it. That might be the way to go, I wish I would have thought of it at the time I did my swap.