I am brand new to this myself and am getting one for Christmas.

So I have been reading around the forums and as far as I know the duopro is a kr808d-1. There are a bunch of different companies that sell "their own" version of the same model.
From what I have been told it just comes down to some are originals and some are knockoffs, but they are all basically the same and you just want to
shop around for a compromise of the best price and the most reliable and customer friendly vendors.
It seems that the site that sells the Duo Pro is more expensive then others.
Try this forum and
thread, it seems to be very informative.
If I am wrong about any of this, please, someone correct me, as I need to learn all I can as well.
I tried posting the links, but because I only have one post I can't, but there is a model specific forum within these forums for the KR808D1, try that. There are two threads that list suppliers and such, try the,
"Common Names, Compatibility and Where to Get One", thread.