I don't think that the brand makes as much a difference as you might think. 100 watts is 100 watts. I bought HyPower panels on ebay. The important thing to remember is that shading is the real problem for marine
use. Just the shadow of your hand can cut the output of a 100 watt panel by half (as previously posted here--with a u-tube link of the drop). The shadow of your mast
could cut it even more.
You have to get mono panels, of course, and I recommend getting several smaller panels instead of one big one. I bought 16 25-watt panels to put on my catamaran
roof. If one is shaded (or broken, for that matter), I only lose 25 watts instead of 100.
Some people recommend flexible panels, but I was afraid of the durability and having to replace them more often. You may still want the flexible anyway. Still, get several smaller ones for the shading and breaking problem. My small panels (about 1 foot by 2 foot) will follow the gentle curve of my big roof.
Oh, the reason the shading is a problem is that to get 12 volts (actually 18) is that it takes a series connection of 36 solar cells to get there. Shade one, and the current
drops for all. The panel's current
output is limited by the smallest current output of any one cell (the series connection). It would be great if there could be a diode on each cell, but the voltage drop because of the diode is greater than the cell's output voltage.
Happy hunting (I am an Amazon and ebay fanatic---and the off season prices are great).