I didn't vote because I won't be signing up (owning the eire, and all), but I'd suggest you use the eilish. first off, it's the smaller of the two, so it's cheaper and I would presume easier to send travelling, and it will likely mate better to the varied tryout locations. Also, it is the one for which you offer the floorstanding model. Thus, if someone were intrigued by it's sound, but wanted a floorstander, well, there you go.
But really, send out the one that you think does best service to your business, and that you can afford to write off as a loss.
And while I'm sure I don't need to say it (when has that ever stopped me) make sure that the idea of the tour is posted on the two channel and audio central forums in order to build the kind of audience that you need to make this a go. You might post this poll question there if you really want to know what interests the masses.
Good luck with it mike.