I wouldn't get any smaller, and if you go bigger, make sure the light's dimensions fit and so forth. Look at some of cartys grows, I think he is using that light, or the spider farmer "1000" model. TSW2000 I think would fit, double check, more expensive....but more light.
Also, the tent you show, 63 inches tall is way better than the shorter one. Pots take away some height, light can't be right up next to the ceiling so that takes more. And, of course lights need some room over the canopy, which eats up a little more.....
Bubba