Ok Ill defer to Lax's superior experience in these areas. So putting the swap file (1.5 X your system ram?) on the SSD and WoW on the SSD seems yur best move.

It looks like 150mb/s read and 100mb/s write for a $240 drive.

150mb/s is SaTa max bandwidth

2 of those drives will saturate a SaTa II bus.