If you want the Velvia for the saturation, shoot it at 40 instead of 50 - it takes it from ridiculously over-saturated down to just punchy as all get-out. With light being as intense as it is in that part of the world, I'd frankly opt for nothing faster than 100 speed unless you know you're going to be shooting a bunch of night shots hand-held. This is in part a personal preference, as I like to be able to shoot in full daylight without being stopped down to f22 all the time. Especially for people shots, it is nice to be able to throw backgrounds out of focus to at least some degree.