A couple of weeks ago I went to a NNJ Region PCA Boxster/Cayman tech session at PowerTech in Rockaway, NJ. One of the shop owners spoke at length about this oil sump extension kit that's very effective at dealing with oil starvation:
Mantis Sport > Products
One of PowerTech's owners has this on his Cayman S and loves it, and they have a number of customers who are serious racers that have found this kit to be very effective. I'm no expert, but it seems to be a proven, cost effective solution.