convert RB to Pantone

How do I convert RGB(0,74,143) to Pantone? Or at least the closest match?

Also, what is the most widely used Pantone style used in the printing 
industry? In the palettes tab, there's 11 different Pantone styles. When I 
ask the printer what he uses, all I get is 'just Pantone'. But the numbers 
vary from palette to pallet. What should be used?

thanks