I'm interested in purchasing 19 inch hub centric wheels for my 08' G35X...don't want to use any centering rings, spacers, etc... I'm pretty sure HRE will make the wheel to OEM specs but they're extremely expensive and I want to explore other options. Any suggestions? thanks in advance.

Also, is it possible to use the 19's from the M with a 245/40 tire?

 

There aren't too many companies that make hub centric wheels. Best bet is to find a wheel you like and contact a dealer or the company and ask if they can make it hubcentric, also it has to be a company that custom builds wheels.

Also the M sport wheels come stock with 245/40 tires, so yes.