Edit: 1st would be unfair in short blocks and might unsettle the comrades as there might be only very few be paid on such blocks, the second option however punishes the poor war veterans that have to calculate hashes in their head and can only submit one solution every second week or so.
The final pool model should be PPS or PPLNS. Initial stability of the pool will be realized with multi-pool mining, guaranteeing payouts for contributions. If your workers are found to be in the lowest x% least performant workers in the pool, the administration will take corrective measures of course, while top performance workers will be appreciated by the administration. Otherwise the majority of the miners will receive equal shares irrelevant of their contribution, as the Great Doctrine suggests!