I would highly recommend getting the flash done BEFORE you install your Soundz system. It is way too tempting to 'turn it up' and without the recommend flash, you can possibly damage a component of your system. Even though you are required to do the 10 or so hours of ' break-in' period at flat bass/treble and no more than 50-60% volume, you will still be tempted... TRUST ME on this.
IF your INDY has Digital Tech... GREAT!!! wait for him.... or raise a stink at HD or go to another one.
As Bryan stated... its all of 15 minutes to hook up to Digital Tech and check the appropriate boxes. I have even done it myself at my local HD on my 15RGS.
Just ensure you give whoever is doing your flash, the flash instructions provided with your system from Peter.... it is imperative to have them do EXACTLY what the sheet says to have your system perform at its optimum... WHY? ( you might ask ) Peter and his crew tune these systems to work with flash they provide you instructions for BEFORE they box it up and send it to you. So if your flash is not EXACT, you could be lacking the performance it was tuned for.