Dunno about stock arches, but wider ones can fit serious fronts, see 245s on em a fair bit, and mines got 235s with zero rubbage even seriously low with tons of lock and minus offset.
And with the lights, well, when you can get them under 900kg even with a serious cage and metal roof/doors, it shows how much weight there is in things. Im on a serious weight saving thing on mine, everything else is fine and dont wanna affect anything, just want it faster, so ill jus add lightness.
Hers my solution to heavy ass lights, literally the last brand new set in the entire world it seems, infact the common story has always been they have been unavailable for many years, but not quite...
Comprehensive bit of kit, even a plug n play wiring loom n fully adjustable beam for MOT purposes. Best of all, it all weighs around 2kg, stock stuff, thanks to the motors, weighs a LOT, exactly the amount im not sure.
One my new tailgate turns up that will be a godsend, it weighs 6.5kg all in, stock one, even without the rear wiper, weighs 26kg!