comments:
nova_asgard posted on r/watercolor5d
I think for portability's sake something with pans is better (although if you prefer tubes, you can get empty pans for cheap and refill them). Have a look at these Cotman sets (I'm showing Cotman here because it's the range you originally chose). The "sketcher's pocket set" has a tiny box and comes with a travel brush. The other thematic sets (landscape, floral, etc.) are also good if they fit what you want to paint). This other set by Sakura Koi comes with a water brush instead, and there's room for a tiny sponge. I've moved on from Cotman to W&N artist-grade now, but I still keep the Cotman box I had and slot in pans because it's so compact and handy.