Is that Boss controller pretty good?
I've been looking for something to throw tunes in. But I been really wanting something with a volume knob. Buy in a smaller package like that.
You will get a thousand opinions on the Boss stereo head unit, they are popular, cheap and widely used, here's mine.
I think there are volume knob heads in this style of receiver. JBL, JL Audio, Jensen, Kicker, infinity, ROckford Fosgate, ect.
Search Marine stereo.
For basic tunes -
Boss stereo is OK for Boss. It works fine. I use Polk speakers and they sound pretty good eventhough the Boss head doesn't push enough RMS power to them. I've not permanently added an amp yet. Waiting for what I want (NVX) to go on sale.
If I were to do it again, I'd go Jensen or step up to a better audio brand above, with better RMS per channel out wattage and CE certified specs, with a higher end amp.
JMO..