I don't know how you haven't gotten any replies yet, but it definitely is compatible. You will just need to replace the standard battery pack with a Li-Ion one (get the battery holder with the attached speaker) and add a buckpuck. I assume you would be using the same LED module that is already in the saber?
I can't say how easy the Obsidian board is to work with, I have only wired cheaper boards sold by the other guys, but I think it comes pre-wired so you don't have to do any soldering directly on the board.
There may be more I am not thinking of right now, but someone else can probably fill in the gaps for you.
Edit: I forgot you need a momentary switch. If you know how to solder I would just buy the board and do it yourself. If you send it in you will be paying shipping both ways plus an additional fee for disassembly and reassembly. Plus it is a very rewarding experience when you fire that thing up for the first time.