Hi, yes, they do make a satchel! Here it is:
http://www.neimanmarcus.com/p/Alexa...ements%3D&eItemId=prod161660141&cmCat=product
Sad story about my shopper tote...I sent it back b/c it just didn't sit right when I put it on my shoulder (the wide bottom of the bag hit at an awkward spot under my arm) and was going to order the same studded bag but in another style Neimans had that was a flatter shaped tote...I stuck mine in the mail and then went to order the other one and it was all sold out!And now I can't find it anywhere...boo.
There are not a lot of them around and they do indeed sell out in certain colors or patterns.
Suggest you call NM or Saks. They can locate what you want in-store. Also have you considered trying some of the UK department store websites such as Harrods or Harvey Nick's, if you do not mind the trouble, or Net A Porter or even (yes!) Zappos.
While I love McQueen, you may want to look at the similar bags by Valentino. The leather and workmanship are teriffic. I would say the AMQ styling is a little more "downtown" casual, though, and the Valentino more polished.
hope this helps,
b*b