Strongphoenix:
I was thinking of a huge credit tournament like $50k credit that members all could contribute for the tournament
There are ways to make something like that happen without a CC bank.
One way is to have a member (who has sufficient credits) create the CC tournament and add the credits to the purse out of their own pocket. Then other members could send sleeves of balls as gifts to the "creating" member as a way of defraying the tournament cost.
Another way is to have each donating member set up a CC tournament with a credit prize in the amount of their donation. Then only the "collecting" member would play those tournaments and collect the donations. Once the "collecting" member finished collecting all the donations, they could then set up the huge credit tournament using the credits they collected.
Whichever way you go would need to be carefully coordinated amongst all the members of your CC.
Good luck!