DS8/2nd grade has been subject accelerated in math by one year since K, but schedule has not worked out this year. He's been mostly wasting time this year doing Aleks and occasionally going up to 3rd grade math. Met with principal a month ago to discuss upping overall challenge level at school after discussion with multiple parents whose kids need more challenge.

Principal suggested going ahead and missing social studies and going up to 3rd grade math every day for remainder of year. She also suggested discussing whole grade acceleration for him. There are about 10 students in the class of 90 2nd graders at his level; only one of them is being accelerated in math with him (both initiated by the families, not the school).

DH and I bought the Iowa Acceleration Scale Manual, filled out the form, and it shows DS is an excellent candidate for whole grade acceleration. However, I, DH, and DS are all ambivalent about it. We would really prefer to keep him in his current grade because:
a) Immediately, he's very happy socially and has intellectual peers in his class. He also has friends in the grade above, although not close ones.
b) In the long term, we're confident our high school choices will meet his academic needs at his age level because of advanced/AP level classes (we live in a large metro area with good high school choices).
c) He's very athletic and we want him with age-mates for high school sports.

Even if we could advance him now and get him back with age-mates by high school, he's so happy socially that we, and he, are hestitant to whole grade accelerate. He's not bored the entire day, but overall the curriculum moves too slow for him and other advanced kids in his grade, and the math scheduling continues to be a problem each year.

He's moderately gifted; a single grade acceleration with another grade acceleration in math beyond that would be ideal for him academically. If he weren't so happy socially in his grade, we'd probably be more positive about pursuing it. He has repeatedly requested more challenge, and even asked for a grade skip last year, but now prefers to remain with his friends. Thoughts?