I went to Xline .co .uk , for my system ,, with the same idea as you , a small trolley system .
I went for a van system , 350 litre , 40` RO , its been in a Kangoo , and now in a Caddy .
100 metres of hose ,its served me really well .
I`m glad i was talked out of a trolley ,I spent more than i wanted to , but 2 years later , I can say i was given honest advice , and glad that i listened to it .
I hope this coment is od assistance