Digitech Express xt looper Jam sync question

Teetonetal

Anyone linking 2 (or more) of these? 

What cable do you need?

Am I right in thinking that each looper can have different length loops?

I already have one and love it, but am thinking of getting 2 more to have a 3 track looper, for way less than the cost of the big boss

I don't need the rhythm and fy stuff on the boss - so it makes no sense for me to get it.