You cannot get those items from PokéStops. The only items you can get are:
- Poké Balls (all levels), Great Balls (level 12+), Ultra Balls (level 20+)
- Potions (level 5+), Super Potions (level 10+), Hyper Potions (level 15+)
- Revives (level 5+)
- Razz Berries (level 8+)
- Eggs
I've gotten an Incubator from a PokeStop at Lv5.