Black suit for a funeral

I need a black suit fast. I'm a pallbearer for a burial on Saturday, and my charcoal suit is not dark enough. Should I rent? Or is there a better solution? I don't fit in any off the shelf sizes, so I'll need to get something that can be quickly tailored as well. I don't plan to use the suit often since I have one very nice suit and that's all I need most of the time. Any advice would be greatly appreciated!