Search "analog pass-through" in www.cnet.com, then find any video camera with this feature. Then click "A/D conversion with pass through". I found 59 results.
woddily is right. Most of them are around 3 years back. You can still find a few late models not too old, like Canon HV30, HV20, HV10, ZR850, Sony DCR-DVD305, 405, 505, HC96.