I'm looking to change to carbon forks and bars to hopefully reduce some of the buzz from the front end
carbon bars on a sub £300 bike? a bit overkill; try double-wrap or gel-padded bar tape.
the benefits of carbon bars have less to do with comfort as with weight saving.
the carbon fork will be a decent upgrade, but don't spend a fortune and expect a miracle.
the advice about tyre sizes and pressures above is also pretty sound...
It won't. What pressure are you running the tyres at?