difficult on Heartbroken. If you want it waxed you are gonna have to let it grow. I would advise that you bleach it as it comes back, I know this is not ideal but the salon will need something there. Perhaps you could call into your local salon and have a word with them, ask them how long it needs to be, not too long I would imagine.
Waxing is definitely the best solution, I have had my upper lipe waxed for about 15 years and now even when it grows back it is much finer and barely noticable at all.
Go for it, it will be worth it in the end.
warpig