There is only one 440 and actually it is called a 440 QE, or Quilter's Edition. It not only accommodates a Bernina Stitch Regulator, it comes with the machine as standard equipment as does the Bernina Walking foot. I LOVE my BSR.
If you check out the brochure, you can see what is included, you'll notice that listed under Pressure Feet section, it shows both the Walking Foot and BSR (stitch regulator) as standard equipment with the 440. Here is the link to the Brochure:
http://www.berninausa.com/webautor-d...chure_ee31.pdf
Good luck with your choice, no matter what you get a new sewing machine is FUN! :)