Overall, I think it looks great. The wig looks fine, though it looks kinda plasticity and shiny to me (and that is just my opinion others may be quite happy with it) but the styling is spot on. The only big thing I see is that to me there isn't much give in the fabric. If you look at Goku's gi there are lots if folds, especially around the tops of the boots where it tucks in and where it tucks in to the belt. If the pant legs and shirt circumference were wider you would get that effect. I would not make the shoulders any wider though. You could also make the leg/shirt longer and not tuck so much into the boot/belt.
I do really like the costume though. It looks wonderful.