I would wait to switch. Some dogs get stool issues when switching and that would not be pleasant while traveling, especially by plane. Rather than starting with prey model, you might want to consider using a premix that you just add boneless meat to, to start out with. Regardless of how you decide to start, most recommend picking just one type of protein to start with, like chicken, then feed just that for a couple weeks, then switch to beef and so on. Don’t start with very fatty types of meat, like mutton or high fat ground beef, wait on those until you know how he is doing on raw. Any meat from the grocery store is still leaps and bounds better than what goes into kibble so yes, use grocery store meats. Just remember, feeding raw is a lot more than just handing the dog a chunk of meat.
