fruit & veg

http://www.photoxpress.com/
 
http://www.google.co.uk/advanced_image_search?hl=en - in Advanced Search in Google Images you can select the 'Usage Rights' to 'For Commercial Reuse' which will filter your search. Double check the rights of the photo on the host site before use though.

I'm not a WP expert but doesn't WP have custom fields functionality? If it does you could set up a simple custom "Yes/No" field so you could choose whether or not to include the content snippet. then in the appropriate templates you'd just query the custom field...
 

{if my_custom_field == "Yes"} My stuff {/if}
 
You'll probably get a better answer from the WP experts