Hi Yannick,
Well done! This is great work and I would be interested in a partial kit. I am also interested in your idea for a 9850 based DDS. I have a back copy of QEX somewhere with an article by an Italian ham who drives one with a PIC. 9850 development boards are available from china for 5 Euros in single quantities e.g. ??
There are also other DDS modules available based on the AD9833 which are a bit more expensive but go down to VLF.?
73s Steve