Medela Breast Pump

Jaclyn
Hello everyone!
I am a first time expectant mom and need help with choosing exactly which Medela Breast Pump to buy. 
My insurance covers it, but it looks like there are different variations to this pump! 
Are there any that you own, in which you wish you had differently? Do you love love a particular version? 
I believe there's one with a tote, one with a backpack, one with a messenger bag...
I just don't know which one to pick!
Please help!!
XO