Deffo need more info.... how you are going to tour, camp, hotel etc and which Eurovelo, north where it might be cooler and you need more stuff, south warmer.
You are lucky, however, you have access to all the cool cheap German Trekking bikes, like
https://www.bike-discount.de/en/buy/...ery_country=48 put some Koga Denhams or butterfly bars on that and you'd have a good cheap tourer for taking in the scenery.