The nice thing about tracing images in Alibre or Atom is that you can scale the image before you start tracing, I have scanned objects and imported the
resulting image into Alibre, scaled it to match the scanned part and was able to create actual sized models to match.
To find out about tablets do a forum search on "Wacom". There was some discussion about using a Wacom tablet with Alibre, but it was quite a while ago. Unless it doesn't matter, I don't think you'll be able to scale the traced result as easily as scaling an imported image. And you'll likely only be able to trace an image that fits on the tablet, so larger images may be out of the question.
Back in the day, there were two tablets that seemed to dominate a lot of drafting offices, GTCO Calcomp and Summagraphics. (I think GTCO was bought out by Calcomp.) They were used for AutoCAD 2D drafting and AEC (Architecture design). You needed a lot of desk space for them too.