I have a "back seat driver" in the trunk of my 56 Chevy but the amp is not working any more. It's from Custom Auto Sound, 2-channel, 200 watts driving 2 8" sub woofers. Obviously this isn't a system that will blow the windows out but Impressing others isn't my thing so I don't need much. I've been given conflicting opinions about what to get to replace the amp.... Either a 1-channel mono class D unit or simply replace it with a similar 2-channel unit. I don't know diddley. Any advice? And what should I expect to pay?