>>7343667the irwin dragonballs are too big for earth balls, and too small for namek balls. the best in scale earth dragonbals are the ones included with each of the DB figuarts, but at the moment only 4 of the hypotechical 7 figures with a ball are made. the GT themed figures of the old hybrid action line also include them, but again, they only made 4.
pic related is goku 2.0 with figuarts kid goku's ball and and hybrid action kid goku's. the hybrid action one is a bit smaller, and its decal is a little faded compared to the figuarts one.
i recomend you go for the DB figuarts since they are easier to get now, and it's far more possible to get the whole set soon or later.
for namek sized balls, i guess those real life replicas from bootleg shops can work