To be honest what you really want to do is get hold of, or go to your local printer, and look in a swatch book. There will be Pantones that you simply can't reproduce in 4 colour that might be the best fit with your logo. For example orange in 4 colour is terrible, however the Pantone (021 i think) is fabulous.

Then take the Pantones as your proper reference and use a 4 colour swatch book to find out your CMYK breakdown.

He is correct. Pantones use non-process colors to mix the inks to access colors not possible in CMYK (and vice-versa.) This is called the color gamut of the two systems. The closest I see is

57, 37, 0, 0 Pantone 196-5 Process (60, 40, 0,0)

52, 43, 40, 6 This one's a warm gray, Pantone Coated shows a 60% K (424) and the Pantone Process colors show 326-4 (60, 45, 45, 0). You might be happier with a 328, and the equivalent of that is 0, 10, 0, 50.

57, 49, 49, 16 This one's almost perfectly neutral, look at the numbers. :-) In neutrals, C is always higher in proportion to the other two due to color contamination. At any rate, I get 70, 55, 55 0 for Pantone Process 326-2.

Thank you bateman_ap and rocknbil for your help!