I had settled on Naugahide to cover my Gaucho, got it from Mosehart-Schleeter her in Houston
Mosehart-Schleeter Company Inc. :: Products | Naugahyde
Also bought foam from them and had a local uhholstery shop that does cars make the new gaucho, using the old one as a pattern. Cost about $600 total
($250 for sewing and that included the armrest).
Ran into the same issue on drapes with JPA Drapes, didn't like their fabric selection so we sent them the fabric. Their price wasn't too bad and included hardware, pins, hooks etc. They did fit perfectly.