As far as actors who were alive and 9-10 when Phantom Menace came out...
Haley Joel Osment is the one everyone who looks into this says should have played young Anakin. 6th Sense came out around the same time though.
Aaron Taylor-Joy was born in 1990, but he was over in England and I don't know that he could have figured the accent out.
Daniel Radcliffe was born in 1989, but that dude IS Harry Potter... I couldn't imagine him as young Anakin.
Nicholas Hoult is an interesting one... but also English.
Liam Hemsworth born in 1990, but I couldn't see an Aussie Anakin...