Which way to finish suspension parts - Powder coar or POR-15?

If you have the money I would suggest powder-coating. I was really lucky when I did my suspension - I had it all sandblasted and went down to a local place that doesn't really do anything for the public. Since everything was clean and all they needed to do was put it in with another large batch - I think they charged me $100 for everything. I was limited on my color choice, but I kinda like the light-gray look. People can tell it is clean, but it's not white.

Check some picture on my website (at the bottom of the page):
http://www.cloudfactory.org/~josh/barracuda/chassis.html