#1 Buy the largest model they make.(the door eliminates the entire front row of slots for rifles)
#2 Buy from someone who can deliver and has the motorized stair climbing dolly to get it where you need it.(2 1/2 hours to get it in my basement)
#3 Measure twice to make sure it will fit. (had to take down a section of my ceiling to stand it up)
#4 Big scopes eat up even more space.
#5 Take the time and bolt it down real good.
#6 Fill it up and figure out where to put the second one.