|"how about this psu"|
No. If you're trying to keep costs down, the PSU is NOT the place to be cutting corners. The Thermaltake is only 65% efficient (vs 85% for the Rosewill), it has dual +12v rails at 14A + 15A (vs a single 50A), has dual small cooling fans (vs one large one), doesn't have active PFC, & has only 2 SATA plugs (vs 6). There are other possibilities than the Rosewill, but IMO, the Thermaltake should NOT be on the short list. Looks like the Rosewill sale is over, so you may want to look at one of the Corsair PSUs.
"why did you pick samsung over seagate"
Have you read any reviews?