With the cooling solution for Deskmini A300, the following are the available options acknowledged in JP DIY community.
Noctua NH-L9a-AM4
This cooler fits perfectly in A300 like it was designed to do so.
It is considered to be the best cooling solution for this rig but the price may sound little high.
ID Cooling IS-40X
This cooler also fits great in A300 but the performance is slightly below NH-L9a-AM4 and the fan noise may become bothersome when the system goes full load.
Though pricewise, it's cheaper than Noctua.
AMD Wraith Stealth
Just as neblogai said, the stock cooler that comes with 2400G/2200G does fit by removing the shroud.
However, it depends on which model you have.
There happens to be 2 models, one with 7-fin fan and another with 5-fin fan.
The 7-fin fan model does fit by removing the shroud but with 5-fin fan model, it does not even by removing the shroud.
Though if you replace the stock fan with 80mm PWM case fan, the height will be lower than 45mm, which is a maximum height on A300, and will fit fine.