What about something like...
A certain amount of countries having a Fed Cup Squad (like 4 players) and each player PMing 1 player each day from the Fed Cup OOP... and whichever team has the most survivors moves on to the next round (or better TB if the case may be)
The problem with that is you will very likely end up with a lot of ties. We could also do it like real fed cup style in that you are scheduled to face a certain player. Say Canada VS USA
Me and you are scheduled as the first singles match for our respective countries. We would each have to send a PM to the manager of the fed cup thread.
Now I was thinking we could do this in one of two ways. The first being, the manager of fed cup will pick 5 matches that each player would have to make a pick from. The manager will also chose in which order the picks will be used.
1) Dani vs Kim
2) Venus vs Patty
3) Maria vs Peng
4) Serena vs Martina
5) Nadia vs Na
So each player must pick a winner for each match. The way the winner of the match will be decided will be whoever survives the longest. If we both get match one correct, we go to match 2, if I picked wrong and died, and you correctly picked you would win the tie for USA even if the rest of your picks were wrong.
The second option would be, instead of having the manager pick 5 matches, each player could chose their own 5 matches and PM the manager in the order in which they want to be used.