Amending recipe for Wedding! : Mixology

Hello all! I need your expert advice in amending the mix of the following drink. In short, I made a post here asking for help choosing the second signature cocktail for my upcoming wedding. Pretty quickly the awesome people of Reddit delivered and I have a clue about what to do!

Earl Grey Old Fashioned

The above link will take you to the site that provides the story and instructions for mixing this drink. Below the body of this post you will find the same instructions copied and pasted.

My issue now is making this cocktail for our wedding, we have a condition to be met. Our alcohol must be sealed, bottled, and purchased. It cannot be mixed at home and brought to serve. Though they are willing to do the necessary mixing on site, I want to make this drink easily made and still taste great. So it would seem my biggest hangup is the making of Earl Grey Bourbon. I cannot do that, so I need a substitute. Short of there being such a drink already being made and sold, what can I use to substitute this? Would Earl grey bitters work? Should I find some bottled Earl Grey Tea to mix in?

I hope this all makes sense and appreciate any help you may provide.

Earl Grey Infused Whiskey

Cocktail

INSTRUCTIONS

1. Add bourbon to an airtight container with the tea bag. Close the container and infuse for 24 hours.

2. To make the cocktail, add simple syrup, both bitters, and infused bourbon to a double-old fashioned glass.

3. Stir well.

4. Add ice.

5. Give it one final stir before serving.