I ordered an SSP undertray today. Shipping ended up making it a bit expensive but it certainly looks like a nice piece.
I decided to go with that and stick with the Aero front lip this Summer. I'll know by the end of the season if I need more downforce up front and will switch it up if required.
I'm thinking about selling the DS2500 brake pads that I bought and ordering a set of Carbotech instead. Other road course guys have been happy with the XP10/XP8 combination.