When my son was first moved up a grade for math, they skipped him one year. Then we all held our collective breath to see how it went. Now he's ahead 4 yrs in math. I think the key is to start slow, let them know that you realize that it begins as a trial, if it doesn't work he can move back. But the key is to convince them it's worth the risk. It sounds like you've done your homework and should be able to stage a good argument.

Good Luck!

Shari
Mom to DS 10, DS 11, DS 13
Ability doesn't make us, Choices do!