Medical characters--most elegant, simple approach needed

Hi. I'm working on created a few Proof on Concepts for taking our course from click next, text and pictures approach to a more immersive experience.

Since we create training for clinicians in the home health care field, I need a range of medical-themed characters, including nurses, PT, OTs, home health care aides, ect.  I've used the illustrated characters for a few mock-ups, but they seems more whimsical, and the content can be very serious, would care, diabetes, hospice, so not sure that's the best treatment.

We have a Thinkstock account and I've found the characters I need, but they are all on white backgrounds, so I can't pop them in a scene. I suspect I need to edit in Photoshop to change the background to transparent (like the Articulate photo characters) and I am not talented in that area so it would be very slow going to create the character set we need. The characters available for purchase through Articulate are not medical themed, not sure there is an easy way to change their clothes. The medical characters I have found for purchase through 3rd parties are a) expensive and b) not quite right.

Any ideas, approaches? I would greatly appreciate any insight and suggestions!

Kelly