I need to purchase tower speakers and amp for my boat. I have 2 questions:

1. What brand is recommended?
2. Do you recommend going with 2 or 4 speakers?

Per http://waterski.about.com/od/marinea...r-Speakers.htm

Rockford Fosgate M282
Wet Sounds Revolution Series
Wakeworks Bullet Twin
Roswell Vamp Spin Speakers