For receiver sights, you have choices for the rear sight as any sight that fits an 11mm dovetail and clears the stock will work. Williams FP-CZ is hard to find. i got one at Numrich. Tech Sights rear will work as will the nice little sight CZ puts on the Camp Rifle, if you can find it.
The front sight is the real problem as it has to be higher, and Williams seems to have discontinued the ramp they used to sell for it. It attaches by screw to a dovetail insert that fits the CZ dovetail, which is different from the more common North American one.
I'm sure you could work out a way to do it, but I've gone with a scope (Leupold 2-7x28 rimfire purchased here). Just too much expense and fiddling.
It's a pity as I still think a receiver sight is the best option for training a new shooter, and the original 452 Scout is without doubt the nicest small-scale rifle I've seen for this market.