500gm would be too heavy for him. We have dummies from 85gm through to 500gm but they tend to be smaller, narrower dummies.
Have a look at Muntjac Trading, they have a complete mix for sale and will offer advice - appreciate you are likely to buy in Germany!
There are also Dokken dummies which have the shape of a pheasant or partridge plus rabbit fur dummies - they all add a bit of variety in shape, scent and texture.
Have fun!
Jayne