Why would you need hub adapters?
With regard to your PM, you need to list the offset as well. 18x8 with 225 tires will fit, but the amount of work required to make them fit depends on the offset.
It seems like you need to do quite a bit more research about how wheel fitment works before you go and buy up whatever's for sale.
Google "offset" and learn, my friend.
Btw, what kind of look are you going for and are you planning on lowering your car?
Also, what is the sidewall profile of the tires? 225/??/R18
It should be 40.
Assuming the tire size is 225/40/R18, and the offset on the wheels is +38, and your not lowering your car, they will fit without modification, but you may rub on small dips and speed bumps.
You definitely need to find out about the tire size and offset at the very least.