I've been running 6-rib on mine for 27k miles now, no signs of slippage and zero belt snaps. Its purely street driven with occasional spirited runs to 8500. I do run a Griptec SC pulley and change out my belts around 10 - 15k miles for preventative maintenance (belts are not expensive). I'm currently on a Gates RPM belt.
On a street driven vehicle, I don't feel 10-rib is a necessity but it definitely won't hurt if you want to spend the extra coin.
Also, a billet Oil Pump Gear & Crank Sprocket should be done with the blower install.