For overall driveability, ease of tuning, & cost effectiveness, the single carb is probably the better choice.
If you have a left drive model, then it is also the practical choice.

If you just want to impress your mates, or if you have a 'balls to the wall' engine, then twins will do it.

The two biggest mistakes that most home tuners make to their street cars is to over cam & over carb their engines.