You don't need to touch your injectors to get the best from your k03, the turbo is the bottleneck not the fuelling.
don't upgrade to a k03s unless your turbo is knackered.. for the extra 15-20bhp you might get its not really worth it.. and is money that could be better spent elsewhere. If you get one cheap/free and can fit it all yourself (remember its not a direct fit, inlet pipe needed also) then it might be worth it.. but even then you don't need uprated injectors, just a 4bar fuel pressure regulator from audi S3/TT to make them work harder.