I have a set of instructions for the Big J if you still need them. Drop me an e-mail with your mailling address if you still can't find a set and I'll send them out to ya.
I made mine before I really new there were photo etch sets for it. It is still a great kit just OOB.
Yes the photo etch sets are worth the money and can range from $18.00 to 45.00 depending on the size and detail you want.
Paul