Assuming the bacteria is unknown, which would be better to take cipro (ciprofloxacin) or levaquin for bacterial orchitis not caused by an std?

Not much difference: Slight nod to levofloxacin, but they cover pretty much the same bacteria. Most non-STD epididymitis at your age is not bacterial, so antibiotics may not help. How certain is the diagnosis? If you just have testicular pain without obvious enlargement or tenderness, I would be suspicious you don't have true epididymitis. Maybe chronic pelvic pain syndrome? (Google it, excellent Wikipedia article.)