A shuttle cica 2002 shouldn't have any issues with either the 160gig HDD or the additional 512 module.
Try if possible, to buy a double sided 512 module as a single sided (higher density) may or may not work.
Examine the manual to see if it has a compatible memory chart.
Crucial.com gaurantee their memory compatibility.
You could see if the shuttle website has a bios upgrade for your model, this will insure greatest compatibility for the larger HDD and memory before the parts are added.
Martin
We like members to GIVE and not just TAKE.
Participate and help others.