Basically hand it back to US so they can gut it to put an RGB LED in it, a Diamond controller and the 2 li-ion batteries.
$395 before tax and shipping, for all the above and the hilt. (new saber).
For a re-build, you would have to contact them and see what they say the total cost (plus shipping) they will require to do the upgrade.
New saber would qualify for the 20% discount for the event right now.
I was actually wanting to do this myself
Keep in mind that if you do ANY modifications yourself, you void the warranty from UltraSabers. If that’s not an issue, then rock on, you go full-out DIY on it, and keep us posted with pics, please!
If on the other hand, you pull back from doing it yourself, keep in mind that, as chalion stated, the price for a new hilt with everything you listed pre-installed is about $400. Well, by the time you send back your current hilt to UltraSabers and get everything extra added (or upgraded/replaced to work with the new components, like switches, power supply, and the like), it will be close to that, PLUS you have to pay shipping both ways (although by not sending the blade in either direction,
that particular expense is lessened greatly). I have inquired about upgrading an existing hilt to have sound (either basic, v3, v4, or Diamond), and the price difference between upgrading and buying another saber is so small that I would rather spend the extra money and have TWO sabers, only one of which had sound.
The only exception to this so far is my Frankensaber, which, when time and money allow, is quite likely to become a DIAMOND Frankensaber, because I simply cannot buy another one of a one-of-a-kind hilt.
You owe it to yourself, I think, to send an email to
CustomerService@ultrasabers.com and ask the questions, just so you can have the information you need. No matter which way you go, we will all sit back out here in Internet-land and cheer you on, wanting pics and maybe even videos.