I believe the most efficient ASIC miners right now from a profitability standpoint are the Antminers, D3, L3+, S9, T9 in that order.
But only the S9 and T9 mine bitcoin and can be discussed here in the
Bitcoin Mining Forum.
The D3 and L3+ mine altcoins and need to be discussed in the
Altcoin Mining section of the forum.
https://bitcointalk.org/index.php?board=160.0As of right now Bitmain does not appear to have any of these for sale. I recommend you wait until they announce a batch for sale, then purchase directly from them.
ASIC miners are expensive and you might as well get a warranty if you are going to spend that much money.
Additionally, there are very few reputable re-sellers of ASIC mining equipment. And most will not sell you a miner unless you pay them more than they can make by mining with it themselves. That means you will pay more for the miner than you will be able to recover from mining.
There is no easy money here I guarantee.