I would go 24.04 if you need GPU and NPU, rkllama works as well as PyTorch to some limits, ZFS-DKMS, V4L Loopdev, etc can be compiled and if you need more recent software: use containers. If you need a more recent kernel and user-land go for Armbian based on trixie (more modernn and debian is still athing ;). No NPU support so far. So far I read with kernel 6.18 we might get a OSS NPU driver included.