So, I had to accept my limitations and scale back this work. The original plan had been to utilise a 3D printer and get involved in some metalwork to create a physical version of this. Originally, it was going to be a Moebius Strip, suspended from the ceiling, with a cue ball following a track around ad infinitum.
As it turns out, a Moebius Strip wouldn't look like the infinity symbol without some horrible twists which would have ruined the visual aspect. Also, I couldn't afford the materials.
It's entirely plausible that I could make a version using Scalextric and baize, so that may still happen. In any case, here's the design as it stands, which is available as a t-shirt if you fancy it - BUYBUYBUY