Hi and welcome
before considering that you should really consider this -
We have just upgraded from an EM4800 to the EM6910 and EM0480 combo.
The difference between the 4800 and 6910 is massive, both in the shot making and milk texturing, along with being able to do both simultaneously.
Most in here will tell you that this pairing is "minimum requirement" and having gone from the 4800 to 6910 I would have to agree.
Sorry I cant really help you with the differences between the lower end SB machines, but saw your post and figured that this one on offer could really suit you.