Canopy

This is my first postpost in this forum please don't be hard on my.

In July I hope to get my first four wheel drive, not sure yet what make but it be a tray model as I am going to put a canopy on it but not sure what to get aluminium of fibreglass.  Only want two doors but got to have a dogbox in the front. /Lift off with jacksjacks or permanently fixed. Would it make a great deal of difference in fuel consumption if it stay on?         I would be traveling a lot over corrugated road therefore it would have to be solid built.

Secondly : refrigeration. I am  tossing up between a small upright or one I can put in a cradle. Been sweating on this for a little while now here on the gold coast

I cincerely hope some one in this forum could put some light on this for me