If you are only new to racing, then the swing rack system will be fine for now. It will take you quite a few race meets to become familiar with what happens on the day, and you will probably end up focussing more on things other than how well your car performs. Things like being able to keep your car running for the whole qualifier, sorting out tyres, getting around the track in one piece, avoiding traffic, marshalling, remembering transponders and so on. Once you are comfortable with the proceedings on the day then you will find the time to worry more about car performance.
My advice would be to race your car as it is, and become comfortable with proceedings before spending any money on upgrades. As your driving improves you will be able to take advantage of the new features and improved performance. You'll probably find that by then you will be looking to upgrade the car to a newer model anyway.
If you are already familiar with racing, I'd suggest an upgrade to one of the later model cars such as the G4JS, MTX4R, NT1 or 720. You could probably pick up a good second hand one from the for sale sections on this forum.