Again, without more information (offset / backspacing, etc) you have NO clue whatsoever if they're going to fit. Keep in mind that the offset & backspacing for something that's NOT 5x108mm native is likely designed for a car that has different suspension geometry or fender flaring than the SHO.
You will not be able to get a definitive answer one way or the other.
Getting wheel adapters is going to push the wheel farther outboard as well, which is going to put stress on the wheel bearings, coupled with the extra 2 1/2" of wheel on there.
You're also probably going to have to run different wheel studs too.
Putting a 225 tire on an 8 1/2" wheel certainly isn't optimal either; I was running 245/45-17 on my 8" wheels. I saw a set of 17x8's with 225's on it that didn't look all that great either. I run 225's on some of my 6" & 7" wheels. The 7's are a great fit (I also ran 235's on my 7's & 7 1/2's in the past).
Your best bet: have him ship ONE wheel / tire combo, and get ONE wheel adapter (say the 1/2" one). You'll get a better idea of fitment & requirements that way, and you're only dealing with shipping one wheel / tire combo twice worst case that it doesn't work out. On the other hand, you also haven't bought the combo that way either.
