Do you mean purchasing guides or user guides or....?
What kind of info are you looking for exactly?
There are several brands/models...but being that all are only available as used machines, going by just brand/model will not give you an accurate picture. Age, wear-n-tear, etc....that's what will be important.
The last 8 track reel that Tascam built, so newer then most, and probably the last one designed by anyone.
Uses 1/2" tape, a pro format for 8 track.
Has DBX noise reduction built in.
Has ports to enable sync options (external other gear required).
There were enough made that there are still parts around the place.
Oh and they sound very good.
However there are good and bad condition machines of all brands out there so buy from a trusted seller and try to find out history of the machine. Some repairs can be very expensive and I only recommend people that can carry out at least minor maintenance and minor repair work ever buy a reel to reel nowadays.