Hello,
my name is Liliana, i have over ten years of experience as a designer, and what i like most is illustrate, that's why i like this project.
Please, visit my Freelancer portfolio https://www.freelancer.com/u/webpolis.html
to see some of the icons i made, in order to evaluate my work.
I can send you more samples, if you want to, and the icon that you requested.
I use Illustrator for this kind of projects, i can deliver you the icons as vector format, and also saved as any other format you may need, like JPG, or transparent PNG, for example.
I found this project really enjoyable and interesting, and i would like to create 100 originals, clear and professional icons, based on the current ones that you need to replace.
I hope we can work together, please, contact me if you have any questions, or if you want to see some more of my work, or the test icon that you mentioned.
Best regards.
Lili.