Okay, I'll weigh in. I hesitated to do so until now only to show that if you ask 100 gun guys for their input on absolutely anything firearm-related, you'll get darn near 100 different opinions.
That said, I simply can't imagine a modern-day Indy
anything that would capture our imaginations as much as his gear does now.
We've seen similar "what if" threads about modern gear. It just doesn't work for me. Can you picture a Patagonia/Columbia/North Face-clad Dr. Jones packing a soulless Glock in some nylon or Kydex holster? (No offense to polymer pistol shooters, myself included).
As Woodsrunner mentioned, Indy's not a gunfighter. That undoubtedly affects the choices of weapon, ammo, and holster (sorry folks, a cavalry-style flap holster is considered a widowmaker in the gunfighting world). If I could see Indy with
any other pistol, it would be the 1911. Classic enough to fit in with the genre, and modern enough to serve as respectable personal protection well into the 21st century if so imagined.