Yup, I'm all over the SIM racing thing here as well. I'm using a PS2 and Gran Turismo 4, various cars. I've looked into the IRacing thing, wow, it's very competitive and very real. Not that PS2 and GT4 aren't, that also is very accurate to realism. GT4 has the Infineon track, both the standard layout and the NASCAR layout, which incorporate different corners, length and such. Steering wheel, clutch and brake setup are the best way to go over a joy stick or hand held controller.
The Cobra on the PS2 is virtually impossible to drive with any engine modifications, by the way. It swaps ends in a heart beat if you even THINK about giving it a little more gas.