I dive WI BC and do just fine! in the northeast I use the 7mm farmer john wetsuit and hoods gloves, so I can't get much more wetsuit on me. Anyway, to your question. Just don't put the weight in your pockets until your ready to dive. Now you may have some permant lead on your back pockets if you BC style supports that and that will make a BC a little heavier ( nothing you can't handle) and thats where the trim comes in. If you need to add more weight or balance even more you can always add a belt or slap some lead on your tank. Or if you find yourself not liking the WI aspect of the BC don't use them and just use the belt alone. I'd rather have the WI option and if I don't like it, just use the belt.
There are a thousand reasons to go WI or not. Drift diving, wreck diving, cave diving, quarry, drysuit etc... They all take different techniques and better ways to rig your weights. I think you need to discuss more of what type of diving or where you think you will go with diving with your LDS and then discuss better options on what your BC should have or not. My point, I like options. And just because it's WI doesn't mean you need to dive it that way!!