Yes it is possible, here is a link to the one I am currently using. I made this for an old galaxy style rom I had because I wanted a simple, light weight boot animation.
http://db.tt/vwPWWxm
To break down the whole thunderbolt bootanimation, first know where everything is located. I use root explorer, but whatever method you choose, navigate to /system/customize/resource and you will see a crap load of files. Flick all the way to the bottom as there are two that we are interested.
VZW_Airwaves_1.mp3
VZW_bootanimation.zip
The mp3 is the sound to the bootanimation, and the zip is the animation itself. If you simply want to change the sound, simply rename any mp3 to VZW_Airwaves_1.mp3 and replace. Nice and simple. If you simply want to replace the bootanimation, rename any bootanimation.zip to VZW_bootanimation.zip and replace. If you want to replace the bootanimation AND sound, then you need to modify the vzw_bootanimation.zip so that the sound still gets called up.
If you would like any further information regarding bootanimations feel free to shoot me a message or post here as I spent A LOT of time over the past while tinkering =)