Hey there,
I found DietPi to be a nice, very slim alternative debian image for SBCs. Its running smooth on my raspberry pi 2 (stretch beta) with way less memory consumption than my prior raspbian image.
It offeres automated Nextcloud installation, but not yet fully as recommended, so I opened a github issue to optimize this: https://github.com/Fourdee/DietPi/issues/1067
Everyone is invited to add his/her ideas/recommendations/corrections.
Best regards,
.