What kind of hard drive should I buy?

[EndlessMidnight]

I have a Sony VAIO SVE14125CLW with a Hitachi Z5K500 HTS545050A7E380 hard drive that I need to replace, I'm wondering what kind of hard drive I can buy, like what are the requirements based on my PC.
I emailed Sony support about it but they weren't able to give me the information.
I'm wondering about the differences with my current hard drive, I've found some hard drives I could buy but I don't know if they'd be compatible, for example can I get a hard drive with a faster speed or bigger storage capacity? how about a slower one? that's the kind of stuff I'm wondering, minimum/max requirements, I hope this made sense, I want to make sure I get the right one.

VAIO PC specs:
http://www.pcworld.com/product/1288320/sony-vaio-sve14125clw-notebook.html

Hitachi hard drive specs:
Interface: SATA 3Gbps
Capacity: 500GB
Sector Size: 4K Advanced Format
Areal Density (max): 636 Gbit/sq. in.
Data Buffer: 8MB
Rotational Speed: 5400RPM
Latency (average): 5.5 ms
Seek Time (average/typical read): 13 ms
Physical Height: 7mm
Weight: 95g
Power consumption (W):
Startup peak (max): 4.5
Seek (average): 1.8
Read/Write (average): 1.6
Performance Idle (average): 1.5
Active Idle (average): 0.8
Low Power Idle (average): 0.55
Standby (average): 0.2
Sleep: 0.1

 

[ThatVietGuy]

You can use any SATA 2.5" hard drive to replace the Hitachi.

It just depends on your budget and how much capacity you want (more, less, or the same - it doesn't matter).

I would suggest something like this - http://www.newegg.com/Product/Product.aspx?Item=9SIA24G1S87410

 

[Calculagator]

You really don't need to worry about compatibility issues. Like ThatVietGuy said, any 2.5 in SATA drive will work. Since you must replace your drive, I highly recommend that you consider an SSD. Not only are they much faster, they have no moving parts and are much less likely to die in a laptop. The Crucial mx100 256GB is an excellent drive for the price. If you need more than 500 GB then you could consider an SSHD like the seagate ST1000LM014.