CGW has a solid stainless steel guide rod for 25$, and has either 18 or 15 lb recoil springs to choose from. This is what I run in my P-07's.
Primary Machine has fluted stainless steel guide rods with nitride or titanium coatings for $40.99, with a selection of OEM (18 lb?), 15 lb, or 13 lb springs.
I stumbled across another vendor, Grayguns, that has solid stainless steel guide rods, with either factory (18?) or competition (15?) springs included, for $29.
There's someone out on Ebay selling titanium guide rods.