Braking noise/ uneven wear

I have recently noticed that the noise under braking has been getting louder - not squeeking or metal-to-metal contact, just a louder abrasive noise. The car doesnt pull left or right thankfully!

I had a look at the brakes and noticed that the rear pads have worn more significantly than the front - is this normal? I would have expected the front pads to wear more than the rear due to weight distribution under braking and a huge heavy lump of metal at the front??

If changing my pads - what should I go for?

Cheers - and happy new year when it comes.........may the fear of the evil drink be with you all tomorrow afternoon