Hello and welcome to the forum.
The 1.2 500 should have a wire for the wear sensor, but there's absolutely nothing to stop you fitting pads without this; they're dimensionally identical. IMO wear sensors aren't particularly reliable and should never be a substitute for checking the pad thickness regularly. The 1.2 is particularly prone to pads sticking in the calipers if they're not assembled with an appropriate antiseize and this will quickly lead to uneven pad wear and even bending of the pads &/or discs. Decent aftermarket discs for the 1.2 are so cheap it's probably worth replacing them at pad change time as a matter of routine.
Personally I've found the Pagid pads & discs from ECP both to be both good value and to fit well; about £50-£60 for the complete set. The other good news is that changing pads & discs on the 500 is just about as easy as it gets.
This is one job where you can save yourself a serious amount of money by not using a franchised dealer.
You might take a look at
this thread.
