I found this post while searching. thanks though guys.

1.20" front Oem std Offset is in fact ET45.The 10.5" wheels should be ok at the front providing you stick with 275/40 tyres.They will only stick out 10mm!Quite acceptable.

2.Dont go for 315 allround as on the front theses will stick out 30mm and also be 10mm further in!

3.So you have a 10mm (not 5mm)difference in relation to the rear.May be ok without a spacer!Try it and see!Its your preference.You can always buy a 10mm spacer later for the rear.

4.If you decide to go for the 10mm spacer ,then the flares all round would look good.

In my professional opinion,you will be ok with thye 10.5" and oem spec tyres .