Yeah, I get that. I had serious issues with that early on. I was putting extra weights in the storage pockets in addition to the weight pouches and trim pockets. In my 7mm suit, I couldn't dive with a BC that had no storage pockets.
I was going to order a harness but I decided to go the backplate/wing route instead. I think it was a better option, especially since I could position the weight better for good trim. I've managed to drop the amount of lead quite a bit as my weight has dropped and the flexibility of the backplate/wing has helped to keep my trim good.
If I had a harness with all the weight at my waist, my trim would suck. Before I got the backplate/wing and redistributed the weight, I was kicking too much because my feet kept dropping if I was still - and that was with positively buoyant fins. The first time I tried out the backplate/wing in the pool, I was able to hover still without even an occasional kick for the first time.
Even though I'm still over 300, I've dropped about 12 pounds from the amount needed for each type of exposure suit (none, 3mm, 5mm, and 7mm). I'm actually overweighted with no wetsuit with just my backplate, and only need a little extra for the 3mm.