Have you used the LDS site very much? With a bit of cunning, it can help alot. I put some tips for using it in the beginner's section. ALso on their homepage
www.familysearch.org there is a link to their prototype search under 'What's new' .
If you go to the Family Histroy Library catalog - they have several films available for loan and information about other sources about Sidbury. It appears that the Devon Family History Society produced a book in 2004 with indexes for the 1829 Census - that might be worth checking into. There are Parish registers and land tax assessments as well.
There are 19 Clodes in the batch that includes your John's christening. possible siblings for him are Saray Raymond (chr Sep 9 1798 - parents John Clode and Ann Raymond) and Arabella Cload ( chr Jan 12 1780). There are also several children for John Clode and Mary Chilper