the DS214 now on Amazon is 299$ , now only 99$ price difference, I think you should get the DS214 cuz it is newer :)
then you will have to make decision on which drive to buy, 2X WD Red 4TD = 360$, or 2X Seagate NAS HDD 4TB = 350$ , or 2X Seagate Desktop = 330$ , the Seagate is a little bit...