Settings look good. When you say "rippling" do you mean the black density varies across the sheet, or do you mean the sheet is physically a bit wavy when it comes out of the printer?
In the latter case, this is normal. The prints on rag papers from the 3800, including HPR 308, do come out ripply or wavy from the printer, esp. in areas of heavy ink coverage. The key is to less the print dry thoroughly, at least a day, sometimes several days. I recall reading a post from another photographer (in these forums, I believe) where his standard practice is to let his rag prints rest and dry for at least a week. The rippling disappears over time.