The Victrix cataphracts are very good. I have two packs. It might depend on how "late" you want your Sarmatians to be. I'd point out the Victrix cataphracts sprues don't have many helms of the "spangenhelm" type, which is often seen on Sarmatian type cataphract minis. It's more ridge helms and those with an eastern flavour. I'd consider buying a Victrix late Roman armoured infantry head sprue to get more spangenhelm type heads and/or a Dacian Command sprue just to add one or two more archaic looking helms to the mix.