Congrats on the SRT...
Buy, on the extended...
Remove resonator for sound. It's almost a guarantee you'll love it's sound. Even if you have it done it shouldn't cost you over $120.00 and you will gain some power. I am sure you will get all kinds of opinions as, "get the Magnaflo" or "get this or that" all at a far greater cost. I feel you should always start simple. Owning an SRT is more than a game of follow the leader. Unless the leader's right of course.
Where are you located?
Enjoy...
Mike