I bought the RISK titanium ones off aliexpress. So far so good after several years.
Buy them with the seals already installed on the pistons or at least buy several spare seals, it’s a PITA to stretch them over the end of the piston without splitting them so not worth saving 50p buying the “some assembly required” versions and ending up ordering twice.
You also need some very long and skinny circlip pliers, I had top grind mine down to fit down the barrel of the lever.
Unless SRAM have very recently upgraded the pistons and owned up to the problem I’d buy the aftermarket ones, all my SRAM brakes have done it eventually so I’d have no faith in it getting fixed.