Hardware recommendation: which is best

Hello

We're trying to look for the most optimal config for a heavy duty
production server, and the following two are falling in the same price
range from our supplier:

Option 1:
2 x 300GB SCSI (10k rpm) with SAS and RAID 1

Option 2:
4 x 300GB SATA2 (7200 rpm, server grade) with RAID 10

I am not sure how the pricing comes so similar with such different
RAID options, but given the two above I think the second option will
be better for a high volume server where Postgres is the main
application? The only reason I ask is because of so many websites, and
threads on this list, that trump the advantages of SCSI. Many thanks
for any advice!