I think for life that would be to small. I have a very small volitan in my 80, and plan to move him to a 200 in the very near future. If you want to put one in a tank for life I would say at minimum a 135. They can get around 16" or so.
You could actually get away with a 100. Most of what I've read says they will be O.K. in a 75, but most 75 aren't that wide. When you consider this fish in captivity will reach approx. 14".