An archer would probably be easier, though I have not played a rouge. Some people don't like rogues in the EE since you can no longer Sneak repeatedly in combat for zero AP like D:OS Classic, but some do, and there are multiple builds (including a dual dagger mage, possibly using daggers just for the attribute bonuses, or using touch range spells, as well).

Daggers are better

Keeping the rogue viking legend alive! (or how to: make rogue feel decent)

Bows are better

Divinity: Original Sin Enhanced Edition Character/Party Guide

Tactician/EE/Advanced Guide - especially playing on classic difficulty, you really don't need to min/max your characters, but this guide gives a good overview to start with