Meaningful information about Hs 129 operations is rather hard to come by. In the past the best single book on the subject was the magnificent:
Pegg, Martin.
Hs 129 Panzerjäger! (Burgess Hill (West Sussex): Classic Publications, 1997). ISBN: 0-9526867-16 [PzJgr]
Unfortunately this big book is out of print, but as fate would have it, it is effectively about to be replaced by our new book:
Dive-bomber and Ground-attack Units of the Luftwaffe by Henry L. deZeng IV and Douglas Stankey, published by Classic/Ian Allan. See:
http://www.ianallanpublishing.com/pr...9&cat=0&page=1
and
http://www.ianallanpublishing.com/pr...at=1003&page=1
Volume one began to be available in Europe in November 2009 but it is not yet available in North America. However, the part you want is in Volume 2 which is supposed to be released in March 2010. This deals with the SG units including the Hs 129 unit IV./SG 9. The 1942 usages of the Hs 129 are covered in our Volume 1. These books cover the units operations, such as where they were based, what actions they undertook and who commanded.
This should help you out about the general activities of Hs 129 units. If you could get ahold of the Martin Pegg book that would also help.