Castle Corporate Services is the company used by Taxpayers Australia to create Trust Deeds for an SMSF. There are obviously many different companies doing this.
My conclusion from looking at quite a few of these is that you go with the one that your adviser recommends even if that costs a little more. If you incorrectly instruct the organisation drawing up the Trust Deed you can only blame yourself and will (probably) not have any legal comeback.
A few hundred dollars is insignificant in start-up costs and not an important consideration in getting the SMSF underway.