1990 GMC stereo & speakers DEAD, ideas on replacement wanted

[Gotenntitans]

Well, my dad owns a 1987 Sierra and a 1990 Sierra and WAS going to give my son the 87, but now has changed his mind. My son will be getting the 90 stepside. The current factory stereo & speakers are in it and have never been tampered with. They do not work anymore.

My son wants a stereo and speakers in the truck for Christmas. Any ideas welcome. What fits? What doesn't? What should I avoid? What speakers should I get? Been a long time since I messed with stereos and speakers.

Any opinions welcome. Thanks to all in advance. GTT