I need an illustrator for a book that will contain around 50-70 drawings of people in various anatomical positions.

I am a yoga therapist and personal trainer and have recently written a book about the health risks associated with long periods of sitting and how we can avoid them by resting in simple yoga postures. The style I'm looking for is impressionistic hand drawn figures that look like they came from a very refined sketch pad. The images will depict people of all different ages, sizes, and ethnicities hanging out in yoga poses. The illustrations will be somewhat whimsical and not overly detailed so people don't take them too seriously and don't try to force their bodies into unsafe positions by trying to look like "perfect yoga models." The image attached has a style much like what I want in my book. The two colored images are almost exactly what I want. I would like both the black and white and color versions of the images. The cover of the book will be a slightly different concept but a really fun project as well. It will be a play on the children's classic "Goodnight Moon," except the people will be on the ground in various yoga positions instead of sitting in chairs and there will be chairs burning in the fire place. I'm hoping to receive a bulk discount from the right freelancer and then promote them as the illustrator of the book when it is published. To ensure I am signing on with the best illustrator possible I am asking for 4 test images: a person hanging from a pull up bar, a person in squat, a person in a forward fold, and a rough draft of the illustrator's version of the cover.