Haha, yeah, get trashed. Muslims (and their families) love drunk people.
Don't forget to dance with all the children you can. Or at least pat them on the head. The families will love that too. Don't forget to kiss the bride on the cheek.
Do you have a dog? Bring it.
BYOB. Muslims love bacon.
Make jokes about the groom's family being less-wealthy than the bride's, or vice-versa. They'll love it.
*multi-culti-humblebrag*
Seriously though, either just bring them some flowers that you picked/smelled yourself, or give them money/gold. If the muslims are actually religious/strict, they'd probably prefer gold over cash. Especially if it's symbolic/meaningful to their wedding date - Amplified by the idea of passing it down to their kids. Tiny, meaningful gold trinkets >>> cash , any day. Cash gets spent or loses sentimental value immediately, gold is like a long-term goodluck wish...