Tzepesh

I need to buy a pair of 951 rear shocks ('89 or '90), but I find contradicting information on part numbers. Several sites list same PN for 951 and older 924, which I know are different (14mm lower bolt on 951). So what are some correct part numbers for the shocks? Here are some PNs I found, not sure all are correct:
Koni: 8040-1035SPORT
Bilstein: B36-2052
24-020527
KYB: KG4544
553013
Sachs: 984052
105754
105787

Tzepesh

It seems to be the same shock absorber on all 951, from 1985 up, with aluminum trailing arms, and same for S2.

FHMotorsport

That is correct.
I have a set of Koni Sports in as good as new condition available for sale. PM or email if interested.

Tzepesh

I have to clarify a bit my topic: I am looking for alternatives to Koni 8040-1035SPORT. This 951 rear end is going in a VW Beetle, and it will be very stiff for my light car. Konis will not be a very good solution, and I am not interested in the adjusting feature. Also, I look for a part which has the smallest compressed length. Konis are 12.25" (311mm), I would be happier with a part with maybe 11.25" or close to that (270-280mm), and Bilsteins seem to fit my requirement (some sources say 10.41", other say 11.41"). Surprisingly enough, the price difference between Konis and Bilsteins is not very high. I have read some more and found out that most 944 owners are using Konis or Bilsteins, not other suppliers. I guess I will stick to a pair of Bilsteins, as soon as I get clear info on compressed length.
I am also interested in Sachs 105754, which are replacement for 951 , but I do not see anybody saying anything about them.
On KYB I found many not so good reviews, both on dampening factor and reliability.