The quarters on that Honda are largely "paint holders" and little to do with stucture. Yes, it is a "unibody" but honestly, I have replace more than I could count and the inner quarter, rockers, rails are where the strength is at. The outer 22 gauge skin is not doing a whole lot.
I see that 91_crx hasn't responded after the first post so I don't know if he will be back. But if you are do crx, post some photos or explain WHY you want to replace them, maybe repair would be a better choice.