The route via Irun is the closest. Though the day train will take the LGV to south of Tours whilst the sleeper will not. There is of course nothing to stop you taking trains on the same route as the sleeper if you wish.
Beyond Tours, the trains will probably take the same route Poitiers, Bordeaux, Biarritz, Irun, and in Spain, though of course you will miss the gauge changing which the sleeper does. For all other trains you need to change at Irun/Hendaye.
Whatever you choose, you won't be able to do it all in daylight in one day.