So my bike front disc are approaching the 4mm wear limit so ay as well see what people recommend?

Bike at 15k and I believe this are the standard rotors from day one!

Do I just order OEM or go for something different, will also need pads

I have searched this already and came across Bic set up. Just want to see any other options (that are good)

would be fitting these to my SDR, standards are soft and prone to warping

I have these fitted on my bike and they are great although the bolts attaching them to the wheel are not recessed like the originals so they may foul the speed sensor. Mine are very slightly rubbing but you can get a feeler gauge in there. .

Have tried cheaper than OE Brembo discs, false economy as they wore out very quickly (possibly partly due to EBC HH pads), and went back to OE discs now with DP pads.