Do not under any circumstances skimp out on the power supply both the xtreme gear and the cyberpower branded power supplys are junk and will give you nothing but headaches.
The PSU is the heart of the system get a corsair, coolermaster , silverstone or a thermatake.
Usually folks that get the Small ssd are only using it for a boot drive for the Operating system and maybe a few speed intensive programs such as a game.
The have a mechanical drive as a data drive for music, pictures and other data you want on your system
And yes the 1TB drive you chose is a good one.
If you read a lot you should be able to find out how to over clock it your self or just post on Tom's and ask for help on over clocking.