We long ago switched to back and hip carries exclusively. DD's head was jammed under my chin and her legs were banging against mine. She's exactly "average" in length too, so I'm super impressed you're still able to get a 17 month old comfortably in a front carry.
We use a mei tai or a wrap (not as often, I find them hotter, and, well, it's summer!) these days. I can't handle the ssc. DD is 19 months and I'm 20 weeks, and just tie the bottom/waist straps around my ribs above the belly. I'm not sure how it's going to work longer term though, because I am finding it uncomfortable to have the pressure against the fundus, which is only going to get higher!
Anyway, I vote you learn a back carry with a mei tai - simple, easy, comfy. They can still sleep back there, you just have to be a little more cautious in your movements as there isn't really much head support.