We've had our Sabre 31RKTS-6 for over 4 years and it has been very reliable. It is a well built unit.
Sabre installed the 6,000# axles as an upgrade. The GVWR of the trailer you're looking at is around 13,700#. You have to remember that when loaded, almost 2000# of that is on the hitch; it's not all on the two axles. In order to get your trailer to its maximum weight (GVWR), you would REALLY have to load it up with "stuff".
You'll really like the Sabre.
2013 Palomino Columbus 320RS
2007 Dodge RAM 2500 6.7 Cummins
Reese 15K manual slider
M.I.L. in Florida for good!!