is there a simulator or anything to put together one

Hi, RockBand4Ever! I've moved your thread over to Information Desk as that's where questions go.

You'll see at the top of this forum there's a link to a handy FAQs subforum. Within it, there's a thread answering your question.

We have a user-created program, the MAC (Menewsha Avatar Creator) which can be found HERE. You need to download it yourself, and Java is required for the program to work, but all is explained within the MAC thread.

It is somewhat out-of-date now but there is an online version in production, there is no projected finish date for that as yet though.