RE: Third Party Bumpers
I've had a set of the Van Cafe bumpers on my '90 Westy for almost eight
years now.  They have held up very well and have saved me in  two instances
that would have put me in the body shop for some work.
I've looked closely at the Go Westy bumpers and they seem to be a very good
alternative to the stock bumpers.
There are at least two other options out there
http://www.rockymountainwesty.com/
and
http://www.aircooled.net/