Hi guys,
finally I bought the SEF1072xxxx 3DSXL, it's a 4.2-9.0E firmware. 179€ for 3DS XL black/silver, New Super Mario2, original Nintendo AC battery charger, soft cover. Not so bad! ;)
Thanks to davhuit fr help! I will avoid to update!
If, for the moment, i would just run .nds games...