Although I agree with Glen about tweed, you can't wear what you haven't got.

If you were in the UK, I would advise you to look seriously at waistcoats. It is after all a wedding and should be a joyous occasion. Here, a bright waistcoat would not be seen as out of place.

The last thought is this - you can only dress for you and whoever you are taking with you. You can not be held to ransom by the bad dress sense of the relatives of the bride and groom.

Have a good time.

Regards

Chas