Did you watch re-runs of Top Gear on Dave too? I am surprised given the popularity of the show that more people haven't gone for the car-seats-at-home option. You get head rests into the bargain, plus, if you need to re-upholster there are after market seat covers and even those bead things that people had in their cars then.

Essentially all these seats go for scrap so you could get the leather seats from a 7-series BMW to have a mega cool sofa at home complete with arm rest and cup-holders. With a few more bits of wood you could make some outer arm-rests. Heated/cooled seats could be nice too.

Maybe there is a 1990's sweet spot where the electronics aren't present so adjustment can be done with mechanical controls, as per your Astra option. A Transit Van could have particularly good pickings with the right vintage.