Well Chris, I have just completed grinding all of the bad paint and gel-coat off of a 42 Tayana. I used Makita products. I used the mid sized makita grinder, It had plenty of power, and wasn't such a brute as a full size large grinder. For the sanding I use either a 5" random orbit variable speed for finishing, or the 5" regular random orbit for the bulk or coarser grits. The real magic is in the abrasives you will use. Regular sandpaper loads up, and doesn't cut very well, however some very ingenious individual came up with a sanding disk that is called a flap wheel. Mounted to your angle grinder, it is capable of removing anything, and I mean ANYTHING, with EASE! they are available in grits from 36, up to 120. These discs, even at 120 grit, could go through the most tenacious material, and show little signs of wear. They cost about $10 each, but the beauty is that you will probably only need 1. I used 2, I stripped off a total deck of cracked and crazed gelcoat, and the entire topsides of 2 part polyurethane, and primer. They are by far the best thing I have used on my rebuild. I will get you the MFG. name tomorrow. I have seen a similar product by WALTER ABRASIVES, but have not yet used one of theirs, because the ones I have won't wear out! One thing to keep in mind, is if you decide to grind the old away, do it with HORIZONTAL STROKES. that way when you go to trowel on your epoxy, you will have an easier time re-fairing it. Don't do it haphazardly.