Murphy and Milo go Missing

I need an illustrator to do very simply drawings for a 78 page children's book. Murphy and Milo are a dog and cat that get trapped in a van and whisked off to an unfriendly city where they dodge a hostile environment trying to get home. I have tried this clip art and it is impossible to maintain uniformity in the characters that must be the same dog and cat in each drawing. I need project price rather than hourly. Again the drawings can be very simple.