What an Adventure!
You have many of us green with envy at the trip you two are undertaking. I look forward to following along.
On the issue of suspension, I echo the comments of others that you should get that done before venturing south. The other thing I would do while you have access to tools and Eagle Mike is his subframe bolt upgrade. I did it on my 2011 KLR before I even started the break-in. The kit is inexpensive and the piece of mind it provides when you load the bike up is priceless.
Safe travels, David