Depends on price. ATE are original fit on many cars, not sure about yours. I have Eicher discs and pads on the back of mine and they're fine. Even came with all the clips and pins required unlike most of the expensive brands.
I would change the disks if I had any doubt about them, thickness affects their ablity to absorb heat (and if they are way to thin hold the pistons in the caliper) scoring and rusty edges alter the feel and call for more pressure to get the same retardation force, they dont cost too much and the improved pedal feel makes it most satisfying to have changed them.
The rear disks condition also affects the feel of the brakes (perhaps more than the front ones) so dont neglect those if they are showing signs of scoring and rusting.
As to the choice I would try the low cost ones My 124 has done 60k on a set of cheapos (from ECP 4 disks and pads £100) and there is plenty of life left in them.
The min thickness on the new disks was stamped on the outside edge, I suspect that the 3 years of rusting will have obliterated this marking by now.
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