The turning 2 dilemma!

It seems most classes in Reigate are for under 2s or over 2s but what if your little one is about to turn 2 !!! Junior is very articulate and verbal (bilingual - Hungarian and English) but not quite so steady on his feet, not running or jumping yet. So I wonder if the type of group will determine which one he should go to! I can't quite imagine him in a room full of 4 year olds (wouldn't he get squashed?) but then again hanging out with over 2s means he may progress and learn. As I mostly a stay-at-home (let's say 97% of the time) he doesn't go to a nursery or childminder - hence me being so proactive at finding out what's on, so being with slightly older kids may be the answer!