If you're looking for a more lightweight option, hollow legs with a metal rod inserted after firing could be a good option. This will help to reduce the weight of the legs while still providing enough strength to support the glass top.
If you're looking for a more traditional option, solid ceramic legs could be a good choice. Solid ceramic legs are usually thicker and heavier than hollow legs, but they can provide more stability and strength. You'll want to make sure that the legs are thick enough to support the weight of the glass top, so you may want to consider using a thicker clay or adding extra layers of clay to the legs.