60w is totally fine, but often more expensive than the 100w on Amazon for some reason.
Also, they are designed to be used with the cage style fixture. The normal style radiates to much heat back at the bulb and could cause issues with lifespan, possible cause it to overheat. Maybe I’m just overly cautious.
This is what I use but is more like fermwrap than the ceramic heaters otherwise discussed in this thread. I am very happy with this product and using it inside my small fridge fermentation chamber I can raise temperatures to anything I might need.
I looked at the ceramic reptile heaters at one point but decided I didn’t like it for my fermentation setup. I was concerned about uneven temperature and the risk of fire.