It's a matter of personal opinion really, for me I prefer the slightly more fitted style of the windrunner instead of the more 'boxy' aw77, but a lot of peeps would say the opposite
England soccer TF windrunner has been added with the France and Portugal ones
http://m.nike.com/gb/en_gb/pd/england-authentic-tech-fleece-windrunner-jacket/pid-10967366/pgid-11266180
I managed to get an XS for my black one, (have the same issue with my small grey) The UK Nike site stocks them, but I got mine from ASOS, not sure how much that helps but they are made, just not sold everywhere.
I don't think there's a kids chart specifically for tech fleece, probably best bet is looking at the Nike chart or trying on in store. Not sure if this helps.
And do you mean kids XS and S ?
Don't own one either but heard you should size down, this search in thread might help
http://niketalk.com/newsearch?output=posts&containingthread%5B%5D=586410&search=Aeroloft+jacket+fit