The x86 version only supports IDE drives ... I have some hardware that has SCSI drives. Would it be possible to add SCSI support to the x86 version ?

RouterOS5 already supports SCSI

3w-9xxx (3Ware)
arcmsr (Areca)
megaraid (for Dell servers)

It dose not support IBM XEON server or workstation SCSI hardware

find out what SCSI controller this server uses.

LSI Logic Ultra320 for the workstation, I will have to boot a server to say exactly witch one but I know most of the onboard SCSI is LSI Logic

P.S. VMWare SCSI dose not work neither

well, as you can see, currently not supported

Simple workaround ESXi from VMWare