Try
www.thecatconnection.com. Or google "litter lifter scoop".
It is a great scoop. Long and sleek. It cuts right through the litter box as the tines are not flat. They are turned like blades so it glides through the box.
Also, the sides are low. That way less "drag" is put on the scoop.
I tried ergonomic scoops. Horrible.
Thie litter lifter is great. I bought my son one too. You can get them at Walmart I think. The sites should tell you where to get them. I did not get it online.
I also keep an old paint scraper near their box. When there is a buildup of old litter on it, I just pass the scraper over it and it is again like new.