Yeah, it's the same guy (different uniform, though)
Back in the 90s instead of the GA Atom/Atom Smasher homage costume, he used to wear a somewhat uglier (and totally non-descript, if you ask me) uniform. You're not missing much, IMO. The mystery of his real parents was vaguely interesting (mostly because it was obvious it involved GA characters) but the stories themselves were mostly generic fist-fights and little more (again, my two cents)
I'm certain these issues can be found for peanuts.
The writer was Tom Joyner, with Bill Marimon providing inside art and covers.

The defining moment for Damage in recent history was probably his face getting disfigured (sort of the cause of everything he does and his behavior on the current JSA ongoing) and that didn't happen on the Damage series, but in Infinite Crisis, so you don't really need to read it, but like I said, it'll probably be cheap so knock yourself out.