iMac Hard Drive Replacement: What Works

I have a failing hard drive that needs replacement and i was wondering what i can replace it with. the current drive is a WD Caviar Blue SATA Hard Drive
500 GB, SATA 3 Gb/s, 16 MB Cache, 7200 RPM

If i were to replace this with a 1TB drive, do i have to go with a drive of the same specs i.e. 3 Gb/s, 16 MB Cache, 7200 RPM, or can i replace it with a drive that has a 32 MB Cache.

Any response is greatly appreciated.

Thanks.

computers are very lenient to different hard drives, so you should be fine with whatever you get.