Hi Mark,
I started with Aeropoxy products and think they work very well. But about a year ago I switched to West Systems because they are more convenient to use. The graduated pump kit that screws into the containers makes the entire job VERY easy. No measuring or weighing...just count the number of pumps for part 1 and make part 2 match.
For the tips I cut a piece of balsa wood and shaped it to fit...then covered it with 2 layers of fiberglass. It's not really a structural area so it doesn't need to be super strong. After the epoxy was cured, you can add filler...choose your favorite one. Again, I started with Aeropoxy filler, but never thought it sanded that easily. So I switched to West Systems and added micro-balloons. Sands very easy and preparation is easy, too.