You also may want to check ELT requirements when you come to the Netherlands.
Remember however that 8.33Khz spacing is extensively used in Holland, if you don't have 8.33khz compatible radio, you may need to ensure that your routing does not require any usage of these frequencies.
At the moment 8.33 is only used inside controlled airspace (military and civil). In uncontrolled airspace you can still talk to Amsterdam Info and Dutch Mil info on the old 25 kHz frequencies. Also all uncontrolled fields, including EHTE, are still on 25 kHz, for now... So coincidentally your U/S transponder will mean that you will not have to use any 8.33 kHz frequency.
ps: Lille is fine without transponder, but they may complain a little... They will accept you for a Basic Service.
A "Basic Service" is a UK exception to ICAO standard practice. The rest of the world talks about a Flight Information Service. So that's what you should be asking Lille for. (And yes, there is a difference otherwise the UK CAA/NATS would not have made the change a few years ago. Although as far as BS/FIS is concerned, I've never been too worried about those differences.)
But I guess Lille is so fed up with correcting UK pilots that they'll pretend to give you a BS, while actually giving you a FIS.