Agreed with Boats it would be nice to get donor status without the EP. Finishing every single achievement could land you at 100 or even 250 total donated, it's A LOT to do.
Rewards could be total donated to account per each set completed (Combat I, Combat II, Combat III, etc) and Achievement Reward Boxes awarded after completing each block of the set (Easy, Med, Hard, Elite). The number of boxes you get should depend on the difficulty of the block. I think it could be 3, 6, 9, 12 for each difficulty. Personally I think the reward boxes should be tradeable depending on the content