I use a Kramer IWB #3 holster and an 1.5" Kramer double thick horsehide belt. Whatever one uses, I think that the belt and holster should match--meaning secure, snug fit rather than blend together fashionable.
I have a Dalton belt and holster for my SIG, that I almost never use. They don't play well with the Kramer stuff.
Some might balk at a 1.5" double thick belt, but I've not yet encountered a problem with casual pants, dress slacks or jeans belt loops that didn't fit. No one looks at your belt and declares, "Aha! A wide belt! Must be a gun carrier!"