Proper paint?

Proper paint?

Hi everyone! We have the two units pictured below and want to paint the outsides, leaving the inner normal white. I would normally tape everything off and just spray paint, but where we are moving to - we won't have the space to do it (TINY guest room where they will live). What brand of paint would be BEST to roll on and what would be the best brush for the roller? It's such a smooth surface that we are nervous the paint will chip off easily. Other than painting them, is there any other options we can try like would contact paper work? Thanks so much for the help/tips! And I hope this was ok to post here. If not, let me know and I will delete asap :)
Request!

Request!

For what it’s worth…

For what it’s worth…

wildflowers in my garden..and some other things

wildflowers in my garden..and some other things

AND IT FELL FROM THE SKY!

AND IT FELL FROM THE SKY!

I think I got what everybody else got

I think I got what everybody else got

Today on my allotment

Today on my allotment