Espresso is nothing more than hot water pushed through coffee grounds at 7-9+ PSI or pressure. There are several travel brewers, such as the Flair NEO, that aren't particularly expensive and will brew perfectly fine espresso.
The issue, though, is that the main determinant for espresso isn't how you make it, but the quality and grind of the coffee bean. Are you willing to purchase a burr grinder and take it with you on vacation? If yes, and if you want actual espresso, then this is the best route to go.
From experience, a Moka pot will give you something slightly (but only slightly) closer to espresso than a french press. However, I've consistently gotten much better results with a french press. As far as going with an Aeropress over a french press, the former should give a cleaner result, but my best guess not ever having used one is that the final result will take about the same, without some of the finer coffee grounds getting into the cup (which can mostly be prevented on a french press if you do it right).