hi i currently have a vf28 turbo on a classic uk 1999 impreza with a tek3 remap

are all vf28s the same or are there different variations if i ever wanted to replace it for the same one if it gave up on me could i just swap it for another vf28 with out having to do anything else?

as i have seen some for sale that have come off a v6 sti and wanted to no if i could buy them as a spare

cheers thanks in advance for any replys