Question concerning my Corsair CMPSU-400CX and components...

Okay, i am pretty new to upgrading computers so i hope yall can understand my query... Ill try to be as thorough as possible with all components i will be adding in since i dont trust any of the PSU calcs as they varied in answers.

I recently bought this computer the Compaq Presario CQ5220F. (Please note, the computer in the link is the CQ5210F. The 5220 has upgraded DDR3 RAM but otherwise, it has the same specs.) Got it on the cheap for $250.

Now I want to install a...
- PNY 9600GT
- Lite-On Bluray Drive
- a PCI 7.1 Soundcard
- upgrade 1 GB with a Crucial 2GB DDR3 for 4 total GB
- 2 PCI-E 1x accessories (havent decided what)
- an additional fan, a Enermax 120mm Magma for cooling

I plan to use various USB devices. (KB&M, Joysticks, USB flashdrives, etc. upto 7 devices at a time)

Now I ordered a Corsair CMPSU-400CX to power it all since the stock 250w isnt enough at all.

Now my question is, will the Corsair with its wattage and amperage be sufficient enough to power everything no problem (stock HDD, DVD-RW burner, motherboard and the new components i listed) or should i send this PSU back for a Corsair upgrade? I just want to be on the safe side and make sure everything runs smoothly with no issues like the PSU overheating or damaging components.

I will be using this computer for some school work, occasional gaming, and as a HTPC with Arcsofts Total Media Theatre Platinum 3 since it can decode DTS-MA/Dolby TRUE HD and output PCM via analog to my multi-input 5.1 reciever. (IIRC)

Thanks in advance!