Definitely get the Nova engine, after you can put an S3 P/S without a problem and have a very reliable and powerful engine.
Be forewarned that the two main differences between the RS12 S1 and S3 versions was their P/S and the crankshaft with larger timing intake on the S3 engine, but none that cannot be done by a reputable engine tuner if needed.
Have you considered getting an STS RS3 or the new D3? are very fine engines for a killer price. Take a look of it and judge yourself.
[quote=MugenDrew;2684554]BATTERIES are for FLASH LIGHTS, gasoline is for cleanin parts, alcohol is for me to drink and well NITRO...everybody know thats for racing.[/quote] :D:D:D