Went to Singapore GP 3 times - there are lots of things to see and do there - all 3 times I went there, I took the Bay Grandstand (no longer available) - but I only sat there for a while as most of the time, I went to their concerts at the Padang Stage. Back then it was SGD298 per ticket. Well worth it for all the concerts that I attended while there.

I suggest you to take the current Padang Stage Grandstand which is SGD598 each, and it's just a short walk to the Padang Stage which is the main concert arena. Nearest hotel to this location is Swissôtel The Stamford, but since I live at JB, I drive in every morning around 11am and park my car at Suntec City, which costs below SGD30 from 12pm to 1am. It's a short 10-15mins walk from Suntec City to the Padang Stage.

You can do the same and stay in JB, and drive into Singapore daily. You won't have heavy traffic jam due to driving during non-peak hours.

The best viewing locations are the pit grandstands, but they're expensive at SGD1388. If you want the place with great views, and don't want to walk around / view concerts, they might be your best bet. I go there to watch/hear the F1 cars, but most of my time is spent at the Padang Stage