Should you be the one other person who gives a **** how well wheels work, rather than how fashionable they look, here is a list of UK-available OEM F56 wheel weights found on the ETK parts web site (so no money-back guarantees of accuracy):
3.5x15
Compact spare - 5.75 kg / 12.67 lb
5.5x15
Heli spoke 492 - 5.12 kg / 11.28 lb
Steel disc (bare) - 6.86 kg / 15.11 lb
Steel disc incl plastic cover - 7.42 kg / 16.34 lb
6.5x16
Loop 494 - 8.20 kg / 18.06 lb
Victory 495 - 8.75 kg / 19.27 lb
7x17
Tentacle 500 - 9.60 kg / 21.15 lb
Track 501 - 9.80 kg / 21.59 lb
Cosmos 499 - 10.08 kg / 22.20 lb
Race 498 - 10.45 kg / 23.02 lb
7x18
Cone 507 - 11.44 kg / 25.2 lb
Cup 509 - 11.60 kg / 25.55 lb
Vanity 504 - 11.75 kg / 25.88 lb
3.5x15
Compact spare - 5.75 kg / 12.67 lb
5.5x15
Heli spoke 492 - 5.12 kg / 11.28 lb
Steel disc (bare) - 6.86 kg / 15.11 lb
Steel disc incl plastic cover - 7.42 kg / 16.34 lb
6.5x16
Loop 494 - 8.20 kg / 18.06 lb
Victory 495 - 8.75 kg / 19.27 lb
7x17
Tentacle 500 - 9.60 kg / 21.15 lb
Track 501 - 9.80 kg / 21.59 lb
Cosmos 499 - 10.08 kg / 22.20 lb
Race 498 - 10.45 kg / 23.02 lb
7x18
Cone 507 - 11.44 kg / 25.2 lb
Cup 509 - 11.60 kg / 25.55 lb
Vanity 504 - 11.75 kg / 25.88 lb