from the ebay ad description;
- Maximum power = 180 watts RMS (45 watts x 4 speakers 4Ω, 14.4V, 1kHz)
- Do not use original speakers
- Additional line outs and output options: 3 RCA jacks for left channel, right channel, and sub-woofer
- 3.5 mm phone jack for input from iPod, satellite radio or MP3 player
- Switch selectable for 1,2,3 or 4 speakers
speaker ratings listed as well as line level outputs for an external amp if that's your goal..
also selectable for 1,2,3, or 4 speakers so you could run a single modern speaker in stock location..
you mention clear voice as your objective so you could buy an actual analog factory stock am/fm with stock replacement speaker for those results..
depends on how 'original' you're trying to achieve..
as for the modern speakers that will sound decent for music and voice, sky's the limit depending where you're planning to install them..
this might be a good place for you to start to see what sizes are available withing the output specs of the head unit you're looking at..
https://www.crutchfield.com/S-lRuQ8k...kers-Subs.html
good luck!