Website Design: Someone who's never heard of rune-server.
Website Backend: Definitely someone who's never heard of rune-server.
GFX (banners, logos, etc): Chance, but I'd only get one image a year.
Core: Not a question.
Content: Not a question.
Combat: Not a question.
General Client Work: The OSRS team.
Interfaces: Ideally the OSRS team but can make due with paint myself.