You have lots of good options. I wouldn't use any wheel with a carbon brake surface for training. Main reason is they don't brake as well so it's not as safe, and as someone who is on the road 5+days/wk I think that matters a lot, but second reasons are they wear quickly when dirty (or wet and dirty from a passing shower) and also they can deform from overheating if you do big descents.

Do you already have nice race wheels? If not I might suggest keeping your training wheels and getting some 303 or 404 tubies or equivalent (e.g. HED Stinger 3's or 4's) for racing and special use. They are pretty light (~1200g) and very fast.

I personally use HED C2 rims for training. They build up to about 1450g with good hubs which isn't super light but is okay. Also they are not deep so not super aero but still more aero than regular wheels. However, I don't think there's anything better for every day training. They are strong and honestly due to the extra width they ride/handle better than anything I've ever ridden, and I've owned a lot of wheels. I bomb down twisty mountain roads passing everyone in sight and I feel rock solid even in the wet. You have to experience it to believe it. You wouldn't think that the rim would make that much difference to handling but it does -- especially compared with your Ksyriums, which in my experience handle like crap.

_________________
CLB