These are the same speakers I have and those are pretty good prices. You need to get the 213's for the bow (5 1/4's). The 216's won't fit up there. I feel that Hifonics makes some extremely good amps for the prices you can find them on ebay. I would get 2 4 channel amps...the ZX 6400's are really nice. 1 for the 6 speakers in the boat, and 1 for the tower set up. The sub situation is going to be tough because of your stock ballast set up. I have not seen a stock ballast set up, so I don't know about the tanks in front. I would really try to avoid putting subs under the passenger seat. You will lose a lot of bass doing this. So there isn't any room to even put 1 12" sub into the driver's kick panel?
I would also go over to
www.tigeowners.com and ask some questions as well. Someone might have a solution for that.