GURPS is a good system for any setting, but if you want my advice, I say find a system you're already using (D&D, mage, etc) and adapt the setting to it instead of creating a railroad adventure. In a DnD world you could have it where the ruins are in fact ancient repositories of magic, and reaver bots are self replicating construct originally built to maintain and protect the dangerous secrets. In mage you could have it so that "The System" was actually an experiment to merge technology with magic without inducing paradox.

Get creative.