So, I finally had the discs and pads replaced today - didn't do it myself, went to a mechanic, but he at least didn't mind me watching over his shoulder

Can confirm that the pads were of the right kind and everything fitted together (whew

). He also changed the brake fluid while he was at the job, which I was planning on having done anyway. He didn't even need any tool to push the pistons back, just used the screwdriver as a lever while the old brakes were still on.
One problem did occur: after fitting everything together, we found that the brake calipers would now quite strongly rub against the balancing weights on both wheels (so much that one of the wheels couldn't even be rotated by hand), so both wheels had to be re-balanced. Aside from this everything went well, and I'm really happy to have brakes finally sorted (for now

)