Well, I can tell you what I did in Wiz 7 when I had the choice of the pistol, the sword or the shield: I picked the shield.
Given the same option here, I'd go with the shield and here's my reasoning:
1) There are lots of good swords in the game, even if you miss out on Excaliber and the Light Sword as well. There are not so many good shields and most of them are quite heavy. Here's a fantastic shield that is very light too.
2) The pistol requires ammo (or it should -- I've heard some people say it actually doesn't) as well as Modern Weapon skill and it's a lot easier to build up bow or sling skill than it is MW unless you are a gadgeteer, in which case you don't even NEED the pistol.
3) Mystic Ray is only good against Savant androids, AFAIK (not having imported it from 7) so it's relatively useless.
4) I like the neat sound the shield makes when an opponent hits it.
Fortunately, however, I don't have to make the choice since with a little luck and time I can get several light swords as well as a couple of light shields.
