I’m doing this too (GF Preclaiber)
The only 24″ ones seem to be the ones Scott use on the high end 24″ bike and what Isla are using on their bikes. I cant find them retail anywhere, too expensive anyway.
I have tried some 26″ air forks and it makes a dramatic difference to the rake, puts an XC bike into AM maybe DH terrritory. Adults might not think its so bad, but if you think of it in % terms for a kid, actually its a huge difference (for example, the weight of the average half decent bike for a young kid is something like 45% of their body weight, compared to 17% for an adult).
I have some 26″ carbon forks, the rake is still the same so i’m going to cut them down and re-bond them (yes I do have a clue what i’m doing).
Ergo – best option out of the box is but some 24″ carbon forks from Exotic.
Rims? Dont get me started on rims……