As a restoration contractor, I know of no company that sells prefinished poly moldings. However, if longevity of paint is your concern, rest assured these products hold paint extremely well without the seasonal changes and moisture absorption of wood. Using a good quality paint, such as Benjamin Moore's alkyd-modified latex paint, will give you a coating that should last 10 years or more, and look great. I highly reccommend spending $30/gallon for the exceptional performance of their products. You will also end up with the color scheme you are truly looking for, instead of accepting a compromise. Suppliers for poly moldings include: Focal Point Products @ www.focalpointap.com, and Outwater Plastics @ www.outwater.com, as well as Fypon.