Ooops, sorry Offworlder, methinks I have read your post wrong.
Sorry my bad. Reading my post again, I do seem to have actually given that impression that there were multiple SU's available - which there aren't.
An interesting thing about Jager divisions seems to be that even in real life, they were bolstered by additional forces, especially on the offensive. If I remember well, the 100 Jager division actually took the 369 (Croation) regiment with it to Stalingrad (and its doom), and interestingly several Jager divisions that were used to relieve either Demyansk or Ryshev in early '42 also had several additional specialist battalions.
In the game I use them as a kind of short legged PG divisions - they are usually concentrated in one infantry corps with a Panzer army and basically follow in the wake of the Pz Corps. Additional Stug or PzJg units really give them some punch or even better, turn them into excellent 'shoulders' for German pockets.
Actually, its a great pity we do not have the option to motiorise some divisions (with consequent reduction in the vehicle pool) because they would make excellent Mot/PzG divisions due to their high morale.