Like already posted, i don't sell, i mostly collect consoles, so this is how it's gonna be:
* 2DS -> 9.4.0.21E Kids, No problem updating that, cause my kids like to play online and use original 3DS/DS games
* 3DS -> Downgraded to 4.5.0.8 for gateway use
* 3DS XL -> 9.4.0.21E, i'll keep it this way for my sky3ds and DsTwo
* New 3DS ambassador -> 9.0.0.x i'll transffer everything from my 3DS XL to that one (including Ambassador games and certificate) and keep this for online play, eshop stuff and original DS/3DS games.