SIXXER- yes they are to help with the weight of the tank and yes there is a outside wall that supports the weight also, as far as the depth I wish I had more and length but I am very happy with this tank it has been a lot of fun.
AVANSICKLE- I went diving in the Marshall Islands it was mind blowing just to see actual fields of Acroporas and all the other corals I strive to keep healthy and growing it felt like I was a marine Biologist because I had my head in about 25ft of water loving the corals and the rest of the group was more interested in the sharks so anyway it was fun, check out the pics from there in the scuba forum just look for the thread (Marshall Island Pics)
I also wanted to say thanks for all the good comments on this tank as long as there is still interest in it I will continue to add pictures.