Thank you
Only one to buy - I have and enjoy the Leonhardt on Vanguard.

Yes, the Leonhardt Vanguard Historic recording is superb. The
State of Wonder set by Gould is a fine one to have, I prefer his 1981 version with the repeats over the '55. The set also includes a 1 hour + conversation which is essential if you are getting to know the works. I am not a total GG supporter but there's no complaints in his Goldberg's or Bach in general IMO.
Haven't heard the 1959 version or seen it available over here (not looked too hard to find it) but in general surfing I haven't come across it.