Which hard drives for are compatible for an Optiplex GX620?

Hi.  I've tried searching for a list of compatible hard drives for my Optiplex GX620 PC but haven't had any luck.  I can't find available refurbished hard drives for the exact serial number of the original one so need to find out if there are alternatives I can use.  The info on the original:

WD Caviar SE; SATA; WD1600JS-55NCB1;160GB. 

I've seen some listed for WD1600JS, but the rest of the serial number is different.  Not sure if I can use any of them.  I do know some I can't because of the connectors being different.  And not everyone selling refurbished hard drives shows pics of the connectors. which makes it tough for me because admittedly I don't know a lot about computers.   I do know enough I was able to replace the hard drive when it died the first time, but it's become harder to find a refurbished one since my PC is old.  

Trying to do this cost effectively, otherwise I'd just buy a new or used PC or laptop if I could afford one.

Would appreciate any advice you could give, even if it's just to point me in the right direction to get the info. 

Thanks in advance,  Jeff