Sound Quality Old School Amps

Can you guys give me some insight into the old Zed built Planet Audio amps? I am putting together a system for my older Mercedes and want a warm system with good clarity and really tight bass. I have been told to look for old Nakamichi stuff, Butler and US Amps tube stuff, Xtant etc... I don't know anything about the Planet Audio stuff, so if I could get some insight into these it would be much appreciated.

Thanks