Personally I love the basis of the Archon model, but never got along with the 'just about to be mummified' pose.
All Dark Eldar pistols are right handed, so to get him dual-wielding you'll need to clip a pistol off and glue it to a sword arm. Not overly difficult. Wych kits have lots of pistols if that's what you're after, or if you don't mind not running a Sybarite in a squad of Kabalites then there's a pistol and a sword arm in that kit.
As for the Huskblade on his back, you get a pretty kickass looking sword blade in the Archon kit, but it'll be missing a handle when you clip it off his hand. Eldar Dire Avengers have a cool little bit that's a sheathed sword strapped to their back which you could pinch the handle from
either that or a Dark Elf sword/knife bit might have something spikier.
Anyway, welcome to both the hobby and the Dark City!