A few comments before the contest really kicks off.
Zpectrum's suggestion above this is a must.
I will accept the 3 best submissions and will pay in BTC for the best entry.
So you'll take the best three submissions and pay them? Or is there only one prize? Your current statement sounds like you'll take the 3 best submissions for yourself and pay one.
Also, although it's not necessary, I'm sure it won't hurt if you link the light/dark transparent PSDs of your logo.
Best of luck.