My Sybarites have a splinter rifle in one hand, a vambrace blade in the other and a flag on their back. They never have a close combat weapon or anything of the sort, just a regular sybarite with a splinter weapon ruleswise. Heck, some of my Kabalites have various poses of rifle in one arm, some kind of melee weapon in the other. I have never had any problems with them at all, and I really, really doubt you will. Whoever tries to give you crap about such a tiny little detail, well, you don't want to play with that person anyway.
Really, WYSIWYG rule is mostly about being able to tell which model has what. So what half of my Blasterborn actually have Shredders that have their muzzles swapped for Blast Pistol ones? The opponent still knows who they are. As long as you're not pulling something like "well, this guy's gun is red so he's the blaster guy!" and put some effort into converting a model, you'll be fine. It's not like our Archons have anything that represent a Shadowfield or Clone field, too - it's simply understood, because for one, no sane Archon ever goes without them, and two, it's clear who the Archon is therefore it's clear what wargear that model has even if it isn't represented on it.
All that said, if you are worried still, take look at the Raider bits - I doubt you'll be assembling the hanging fellows, so you can take one of their arms, whether it is an outstretched one or one that grabs on to the ledge. A nice advice I'd give is to only glue on the gunner of the raider - the driver not only makes a fine stand in Kabalite (so does one of the hangers with some repositioning of their ankles, check my project log and look for ladies with Dark Lances for an example), but you can easily represent what kind of a squad is embarked on the raider by placing the squad leader in driver's seat. Quick, easy, and very flavourful. Same thing works with Venoms - I bet the sculptors specially made those canopies so that they hold a single model in there quite well.
In any case, check out any of the fine project logs around here and you'll find plenty of inspiring stuff. Dark Eldar are a very flashy army, so don't worry about making your Kabalites flashy looking, too!
Oh, and one little cute tidbit - Kabalite Warrior kits have plasma grenades modeled on their backs. Guess what piece of wargear they DON'T have? ;)So much for WYSIWYG!
_________________Siticus Empyrean Vision
- my Facebook page with various painting projectsSiticus' Empyrean Visions log
- the project log for my Aeldari works and beyond