What size bolts to attach rear bumper plates to body?

[dqa]

I just took off my Euro bumper (had installed for the tow hitch), which has larger bolts that fit in different holes. I doubt I can find the original bolts, so I'll probably need to pick up new bolts at AutoZone, Napa, or even the dealer.

 

[dqa]

Found 3 old ones, but had to get the 4th from AutoZone.

For the record, they are M8, 1.25
The length is 22mm, although AZ only had 25mm.

If possible, it would be better to get OEM, which have the rounded self-guiding tips. (picture to follow)