Is it recommended that we fit a new "Brake Pad Fitting Kit Front - LR016683" when fitting new brake pads and discs?

I'm planning on replacing the disc retaining screws (SDG10000L) with the discs but wasn't sure about the above.

Thanks.

I recommend you have the pins available before you start replacing the discs and pads. When I replaced mine I didn't and the existing pins were seized solid and one was totally destroyed in the process of removing the pads. 2012 4.4 TDV8 Vogue SE Current
2015 E220 with AMG Sport Pack - Currently driven by my son
2010 3.6 TDV8 Vogue - Written off by my son

Bearmach do a brake pad fitting kit, it's a large pad retention pin with bolt securing and then two smaller pins which secure the anti rattle spring.

They will be destroyed upon removal, it's well known they cannot be reused.

This is how mine ended up.

Click image to enlarge

Click image to enlarge

Is there a punch with an inverted conical end to push them out?

Yes, in my toolbox! If you look on Ebay, one can find extended length Torx bits, I buy them and spin the end on a grinding wheel to dish the end. You might be lucky and find a set of Pin Punches someone is getting rid of. Make sure they are Tool Steel. Standard lengths of Tool Steel from an Engineering tool supplier like Cromwell should have what you want. Even a four inch nail can be helpful.