If you can't find one right away, I can probably lend you mine for your race. I won't be riding that bike for the next couple months.

Do you have wireless blips?
If you can borrow someone else's shifters or blipbox to pair, you can use the wireless blips without a blipbox.
I just did this on my TT bike to avoid buying a blipbox altogether. Works great and you can even make micro-adjustments through the app.