Zip and Link Artisan 1500

Hi Mike, Lee,
Thanks so much for your previous answers to my SuperKing Zip and Link questions.
I have one more before I go ahead and make a decision between the Original Pocket 1500 as you recommended and the Artisan 1500 which is the one I had my eye on!
I looked again at our current mattress (just a Kingsize, nice but too small) and it is a Feather & Black Shelly, which is graded 8 firmness. Therefore, in my first email I was incorrect in calling it medium. With this in mind - which of these mattresses would be the best?
Finally, if I place an order, when do you usually deliver?
Thanks
Jane