Why did you buy the I5 if you didn't like the sound. You have owned both an Alpha and I5 in the past so should have known what you were getting into.
I would leave the exhaust the way it is being that by the time you get it and have it installed the T will have already been in the shop a half a dozen times. One the plus side if you go with a Magnaflow or Gibson it will drown out all the funny sounds I'm sure you will be hearing
