If Haynes or Chiltons don't do one, then your only option is the proper one from Toyota. It will cost you a fair bit, and is probably about 6 volumes covering everything. You may be able to just buy the section that's relevent, but it all depends on finding someone helpful, and if Toyota will sell to the public, not many will.
You make an interesting point regarding the availability of manufacturers manual. The Toyota dealer has not refused to sell one, its just expensive. In the past I tried purchased a Volvo 850 manual. The dealer said that they were not allowed to sell it. It didn't take much effort on the telephone to Volvo to point out to them that they were acting illegally in telling their dealers that they cannot sell manuals. They telephoned the dealer in question who was then extremely helpfull in identifying the chapters of the manual that I needed for my particular car. The message seems to be, if you are prepared to pay the high manufacturer's prices for the manuals that are used in the dealers workshops then you can get then by leaning on the manufacturer.
I should point out that the paper-based manuals are freely available for sale from MGR via the Dealer Network to the general public, just the RAVE CDROMS are not, due to the sensitive TSB info contained therein.
Volkswagen has confirmed the pricing for the eight-generation Passat saloon and estate. Deliveries will begin in January 2015, with prices starting from £22,215 for the saloon and £23,745 for the estate.