BF Torino make a wide range of seats which are both well made and look period correct. I purchased a pair of their "early 911 Recaro" replicas which are, indeed, very like the original optional seats frond in many period 911S. Upholstered in gray "body" (cheap and commonly available) cloth, they look period correct in my Super.
Looking at the AH seats on their site, it appears that they are using another version made by BF Torino that they upholster to suit their needs. Do a search for 911 Replica seats or BF Torino seats.
I bought my seats because I got a very good price including shipping costs. Last time I checked prices, the BF seats were going up and were approaching parity with Stefan's GTS seats here in Texas. A friend has a pair of his 911S Recaros in his air-cooled Porsche and they are very well made and fit perfectly. Stefan makes his seats himself so he can better control both quality and turn-around times. He's constructing a pair Alfa "Flying buttress" seats for a guy here on the bb. There's a big difference between Recaros, BF Torino, GTS seats and cheaper seats like Cobra.