Hi im looking for some very large head bolts. I've seen some fibo seats with side mounts use them. think there called fairing bolts but a bay search doesn't come up with any with large heads. Any advise???

button head bolts? are they the same?

yep similar but still dont have large heads!
these are the type im looking for.
Rescued attachment seat bolts.jpg

Probably a conical alloy washer with a recess for a socket head cap screw.
Sorry I don't have a source....

buttonhead and washer on mine

Stagonset
button head with flange

M8 button head with flange, may do for you.

Anodised karting countersunk washers.

like This

Thanks they look like they'll do the trick!!