Understand, I am usually the guy who is in here sneering at people who don't carry full-size autos, because small-medium framed ones are a bit easier to conceal. Most people shoot full-size ones better, and you should carry what you shoot best.
HAVING SAID THAT, the 92 isn't a great choice for IWB carry, and the Ninety-two even less so. The design is pretty much the bulkiest full-size auto. I think when you buy a gun with a rail, you have pretty much decided it's not going in the waistband, especially if you plan on actually using the rail. And if you DON'T plan on using the rail, why get it in the first place?
Look on the websites for Desantis, Galco, et al, and see what's there, but I think your options for IWB for 90-two will be very limited.