I concur with Peek the Geek, something light and sporty but with a more relaxed riding position. Make sure it has some lower gears , you dont have any real use for high racing gears but you will run out of low gears at some point.
Tyre size is a personal thing but many would prefer 25 for unladen, 28mm for a light day-touring load and 32 for a light hostelling load.
The most important factor is correct
fit, closely followed by correct fit.