Two SATA drives in adjacent bays really will build up some heat.
The best fans fit in a bay immediately below the drives.
Alternatively you can get blower type fans that fit in the case. I don't like these they are likely to blow dust all over the computer.
With that configuration you may need some semi-industrial heat extraction system.
I also note your PSU. Antec stuff is very robust. But I'd check you have enough power to cover all you have in that case. My guess is you may need to upgrade the PSU.