Car audio guy here....

I need some advice on a stealthy system. I don't have a head unit or a place for one in the dash anymore. I want to put something in the glove box that I can hook up an aux mp3 to. Radio and all that I don't care about but about anything will have it I know. So I want some tunes but it doesn't have to be high end. Just loud enough to be heard over dumped at the axle 3" exhaust. I have 2 Sony Explode 6x9's that I could use in the back. Although there are roll cage bars going through the old holes so I have an issue there. Then the front speaker I don't know whether to use that weird sized speaker or the 2 4" people are using. Could I get by with just a head unit or probably need an amplifier too?