I know its been talked about before but....What are some brands good ones and bad ones ?

Use MB Quarts or JL Audio!!

JL's seem like big money ? For speakers..But then again thats why I started this..

JL's do cost more, but they are hard to beat for power handling and sound quality. That's what I run in my boat.

Diamond audio.Unbeleiveable sound quality for the money.Just had 4 speakers and an amp installed in my boat and it rocks the water.

JL 10" W6's (older) subs to Percision Power (PPI) 400 watt 4 channel amp with Diamond Audio mids/highs int he truck and a complete Eclipse system in the boat with 4 400 watt amps, 2 12 inch subs and 8 sets of seperates. I have no problems with any of the stuff I have, as a matter of fact I love it all!!

And how many batteries.......

I second diamond audio. Crystal clear and loud enough to break eardrums!

Just the stock two in the boat with the isolator switch. I've never had a problem. When we're sitting for hours at a time I just switch to one battery then switch back to both to start. Never fails.

CDT Audio! Expensive but worth it!!