Realistic Holstein Cows Photoshopped Into Fields

I'm looking for a skilled Photoshop professional to add highly realistic Holstein cows (heifers, so young-ish cows) into two of my field photos. The lighting condition in the photos is overcast, so the cows should be color matched and shaded accordingly. The cows should be positioned in the fields as if they are standing and grazing. I have included a photo ("Cow 3") that shows something similar to what I need. There can be 3-5 cows in the photos, preferably not too close up.

Ideal skills and experience for this job would include:
- Advanced proficiency in Adobe Photoshop
- Experience with realistic photo manipulation
- A good understanding of light and shadow
- Attention to detail, particularly in color matching and positioning