I don't think there are any SD or HDD cams with an av-in for a bullet cam.
Suggest sell Curry's vouchers and buy something else (very likely cheaper than at Currys) that Curry's don't sell, like an (HD) Canon HV10, (SD) Sony DCR-HC95, both of which use DV tape.
Or you could get the Aiptek DV Z300 - no OIS (or EIS) but has h.264 and it's even smaller and much cheaper than the Sanyo. 720p, too.