It won't really matter what pool you use - the expected payout will be about the same on any of them. Assuming 7 BE with 333MH/s each, that's 2.331GH/s. Math will show you that expects to earn 0.00002224
BTC per day at current network difficulty. In other words, even if you were to make expectations, the network difficulty never changed, and the block reward remained static at 25
BTC a block, it would take you approximately 170 years to earn a single bitcoin.
Perhaps you should try your luck and mine on a solo pool:
http://solo.ckpool.org for example.