Desktop hard disks don't need casing. They install inside the computer casing. You may already have the power cable. All desktops have. It's just a question of whether you have an available (unused) one. You'll probably need a SATA cable. Some desktops have extra ones as well. Open up your computer casing and check.

You get more storage and some speed that SSD offers. You won't get the best of both worlds, it won't have the capacity of a HDD and won't be as fast as a SSD. Personally I don't think it is worth it.

ru referring to 2.5" 1tb hdd? if u do, mind telling which shop selling it for RM270? wanna go to d shop & buy . d cheapest so far i found in lyp RM319 (wd scorpio blue 1tb).

Please describe in detail. Is it the surrounding HDD mounting and/or casing vibrating? Or just the HDD itself making a lot of noise? 

You could try putting a heavy weight on it (e.g. a thick heavy book, stone brick, etc), and see if the vibration is still there. Is that PSU touching the bottom plate of that casing?

Vibrations are not good for the HDD generally.

There should be another 1 or 2 screws on the other side as well, to properly secure the HDD. Try putting some padding on the unsecured side (e.g. a strip of thick cardboard between the HDD and the HDD cage). Is that HDD cage removeable?

Preferable not to put anything above the HDD cause HDD does has "breathing holes" to intake and exhaust air to maintain pressure inside.
Your HDD vibration is very normal, spinning at 7,200rpm is very fast, if you try your car engine at that speed and you should know why.
You can put two soft padding on both side of the HDD before screw it to the cage, from the looks the HDD cage should be removable. that should help absorb some vibration directly from the HDD to your chassis, and as I stated before, replace the chassis "leg" with a better one or just put some more padding in between.

Extra note: If you can, try to screw on both side (with extra padding).

I only heard before freezer but not oven 

My son's school data was on the water soaked hard drive, so I put it in the oven and baked it at 60 Celsius for 4 hours. That did the trick, the hard drive works perfect... I backed up all the data, just to be sure. Try to explain to the teacher that you couldn't get your report done because your PC caught on fire. Something like, "teacher, the dog ate my homework..."

I set the toaster oven on about 150 degrees, or so — probably a normal running temp for a lot of devices — and let it warm up. Then I took the drive and laid it on the rack with the top down and electronics up. (I didn't want to cook the circuit board from the bottom element!) Then I stood by and opened the oven door every 30 seconds or so, and felt the drive with my hand to make sure it wasn't getting too hot. I know what a running drive feels like, so I figured I should be able to get it to the right temp without burning the casserole, if you know what I mean.

After a few minutes, I determined that it felt just like a warm, running drive. So I pulled it from the oven, took it to the computer, and let it sit for a couple of minutes to equalize. I knew at that point that, while the outside was crisp, the inside was still warm and gooey. After equalization of the heat, I plugged it in, powered up, and it ran PERFECTLY! I was able to use Helix to image the entire 250GB drive over to a new 500GB drive without a single error!