Peter & Paul

http://www.fishpond.co.uk/Toys/Character-Sets-Magnetic-White-34h-128Set-Quartet-Character-Sets/0034138250211?utm_source=googleps&utm_medium=ps&utm_campaign=UK

or letters could be spraypainted:

http://www.inspiredbycharm.com/2013/08/diy-gold-magnetic-letters.html

or they could be done on the laser cutter?

wall a - 3,380 x 1,700

wall b - 2,100 x 1,700