This sounds like an awfully sweet and beautiful passion project.
It shouldn't be any trouble to pick up the general style, if you are strictly looking for something in accordance with your example, as I assume you are looking for a similar level of detail and intricacy.
I specialize in absolutely custom photoshop design, top-tier image processing, and especially dynamic portrait painting, with a great affinity for anime; there is perhaps no one better suited.
I am also happy to adjust accordingly, as it is important to consider, budget and time greatly affect the result.
This wholesome concept would be a true joy - to give it the attention it deserves.
I am interested to know what the final dimensions you are looking to present the piece?
Most importantly, when is the birthday date?