I need some help as I do not know a lot about rims and tires...

OK I am going to purchase a set of Work Wheels VS-MX off someone...The size is 18x7.5 the bolt pattern is 5x114.3, came off 99 Eclipse gs-t. Offset is +45
I have a 2003 accord v6 coupe...and his tires are nitto 555.
The problem is two of his tires are 235/40/18 and the other two are 225/40/18...He did this becuase of his turbo...
My question is how should I set up these tires on my car since they are different size...Moreover, which ones should go in the front which ones in rear? I checked a speedo calucator and I will be off by liek 1~2% but how would I calculate since tires are differnt size? Please help
Will this rub agasint my car, it is on stock springs and all...will the 45 offset make wheels stick out a lot? or not at all?