OMG!

Took a nap and missed the party
Natasha.........I've got both the Xtar and Nitecore chargers......love them. About button top or flat top batts for the vamo.....flat tops are fine. They are what I use. The first vamos that came out had a small issue with the spring in the end cap......that may be why button tops were advised, but that's been fixed........so you should be fine with either.
When you get it.... come on back here and everyone will help you to get the right settings on it. You want it in RMS and power...which means watts.......instead of volts.
One really nice thing about getting an advanced device........you'll get an error warning on the display when there's a short......and it won't fire
You can try an 18650 batt if you want.....but like most here, I only use mine in the shorter confiuration