I could be accused of mistrust of the forum participants.
You shouldn't trust all users 
Quote
If you have an offer and are ready to pick a winner, post it, I will add these terms to the rules
How about this: After locking the topic on December 16, you post a numbered list (start with number 0, not 1) of qualifying candidates and a winning Bitcoin block 12 blocks in the future. Don't edit that post anymore.When that block is mined, and let's take block 659343 as an example, you take the hash:
00000000000000000009a4f6f21e40f4c24eb7d0d17be6f35166c894ed93cccf
From this, you take all numbers: 00000000000000000009462140424701763516689493, then for convenience the last 9 digits only: 516689493
Say the list is:
Code:
0. userA
1. userB
2. userC
....
69. userBQ
1. userB
2. userC
....
69. userBQ
To get the winner, you divide 516689493 by 70 (one more than 69) and take the remainder: 33. User #33 on the list wins.