[Ti] Suggestions for Replacement Hard Drive?

[Jerry Krinock]

We need a new hard drive for my wife's old 800 MHz Titanium powerbook.  The
hard drive is described in System Profiler as:

ATA-4 Bus 
IBM IC25N040ATCS04-0

It's 40 GB, but I don't know what "ATA" stands for, etc.  Can someone please
translate the above into some keywords that I could use for searching eBay
etc.?

Also, any advice on where to get a replacement?  Anything equal or better to
the existing 40 GB would be fine.

Thanks,

Jerry Krinock