not sure if i'm ready for a NASA HPDE though? where's a good link or write-up describing how it's structured and what the event is like? i'm being conservative as i like the added safety of events like PDA where there are strict rules, passing in very limited areas with point-bys only, and you don't need a roll-cage inside your car.
i get the sense NASA might be better suited for a more seasoned driver (i only have 5 events under my belt) with a dedicated track car.
NASA is significantly safer. The last PDA event I attended they let most drivers loose w/o an instructor and very little classroom instruction. With NASA until you've attended several events with them and are signed off by at least 2 instructors you can't solo. Same passing rules or less in effect in lower groups. Both are great to run with.