your boss may need a small graphics tablet , which was a laptop input device you can eaisly editing and make signature . there are two type of drawing tablet . with or without screen .
As for me, I’ve been used for a long time XP-Pen Artist 12 https://www.xp-pen.com/goods/show/id/380.html 11.6" IPS Pen display monitor , and I found it really good and cheap screen tablet. that’s only $250, if you want to be on a lower budget. but this will allow you to draw directly on a screen for a more natural experience. I’ve been working with it when I needed to create logo of educational website .