Need help - still photo software

[Dr. M. Burek]

I've never been much of a photographer, so I've not needed "special" 
photo software, until now. I have 50+ photos in digital format, that 
were taken with a regular film camera. I also have the negatives, and 
the prints. However, 90%+ of the photos are out of focus, and blurry.

These photos are of work on parts that I did (not computer related), 
that cannot be re-shot. They are irreplaceable. So, I'm willing to spend 
money to get a software package that will (hopefully) enhance the 
pictures enough to be usable. But, I don't know what to get - hence, 
this request for help.

I have iPhoto, but it's useless for this. I've thought about getting 
Photoshop, but I don't know if the Mac version is the same as the PC 
version, with the same or similar features (I have Photoshop 6.5 for PC).

I need suggestions on what software to get. It MUST be able to enhance 
very blurry photos, and sharpen up the enhancement, enough to be able to 
see what's on the photo. Extreme enhancement to the point of 
"normalizing" the photo would be better. It must be able to run on 
either OS 9.1 or better, up to OS X 10.2.6 or 10.2.8, on a G3 400 MHz, 
with 192 MB RAM. Disk space is not an issue.

Would Photoshop be good enough for this, or do I need something else? 
All suggestions are welcome.