Molding questions and fender question

Okay I am almost to the point of putting on the aluminum and I was going to use insert molding on the roof/wall joint. I have called all the RV places around and they only have it in white. I need it in mill finish in 16ft lengths. I have two questions:
1) Where can I get this stuff?!
2) If I have to get it in 8ft sections how do you splice them together and make it look good?
3) My other option would be to use regular aluminum angle and anneal it. Has anyone done this? Any pointers?
Fender question:
How do you bolt the fender on through aluminum skin? I assume you don't use regular wood screws through the fiberglass and aluminum, correct?
Thank you.
Ryan
1) Where can I get this stuff?!
2) If I have to get it in 8ft sections how do you splice them together and make it look good?
3) My other option would be to use regular aluminum angle and anneal it. Has anyone done this? Any pointers?
Fender question:
How do you bolt the fender on through aluminum skin? I assume you don't use regular wood screws through the fiberglass and aluminum, correct?
Thank you.
Ryan