Can you please tell me what config did you have, and if it managed the load ?
I suggest you buy IBM server with E5-2620V2 processor, x3650 M4
Don’t know how much memory you need, but I think You will need to add some 00D5036 .
Do you need to have fast SAS 10K drives or slower 7,2K SATA ?
To get RAID 5 additionally with 512MB Flash memory for the controller you will need to add 81Y4487.
But i'd opt to use RAID 10 for max performance.