Creative tank will allow the infinite supply of fluids in creative mode. There will be no recipe for the tank and the graphical appearance should be similar to the BuildCraft creative engine.

The key will be to override the drain() and fill() methods of the tile entity such that on fill() the tank fills 100% with the provided fluid, and the drain() method returns fluid but doesn't actually empty the tank.

Seems to make sense that this tank would be a nominal 16 bucket capacity. Unless somebody has another idea...