Minelab and garret make great pans, both make matching classifiers/ sieve .
A snuffer bottle is almost a must.
Bunnings have a good range of cheap plastic scoops$3, handy.
And a good light hand pick , fluro green handle $7.
And a small shovel $7
A strong 10/15 or 20ltr bucket.
Old back pack to store gear and stuff in. Op shops are place to get one cheap.
$60 ball park
Yabby bait pumps from BCF or Anoconda are great for sucking up material from cracks into your bucket or pan.
Google miners den perhaps.
Depending on his size, a 15" pan might be to big for him, 12" s is a good size.
Later on if he is still keen, Gold Rat make the best river sluice. Vortex dream mat has almost become a given in the trapping mat for gold these days.
Gold Rat also make this.
https://highbanker.com.au/collections/all