If you wanna have some NA fun, just splash out on a bigger set of cams, ITBs, ECU. I had a shiteload of fun with mine! But once I had spent 5-6k on my NA setup I was disappointed because I could have spent similar money on a turbo setup! I shrugged it off at first, thinking NA would be more fun, but after going in all my mates turbro cars I had to change!
It gets expensive to get a lot of power from a NA setup and still have good street driveability! But then it was much easier to rego!
All depends on what you want outta the car! Nothing beats screaming up/down a mountain with rock walls echoeing the induction noise of ITBs! But if you have ever thought about going turbo, now would be the time to really sit down and think about what you really want in terms of bang for buck!
Goodluck!
Cheers.
-Whitchy-