Well your space is 3x1.75ft give or take so I would look at the shape of a panel before delving further. The 260X is a perfect size for you. Other panels are either going to be square/rectangular which will require 2x for best coverage in the corners, if you intend doing two plants at a time you can bank they will fill the corners and it then becomes necessary to give as much light in those corners as the middles. If you intend doing it, DO IT RIGHT!!
I'd say anything between 200W and 400W is enough power and would give you plenty product. Whatever a panel promises to do bump up to the next panel up. There are plenty choices however.