C 2400 with P ?? ,what is better E 460 E E 550 ??

can someone help me on this,the sellers are all telling me different things, so i downt no anymore what to do,
is it better to have a pre amp and rear amp, ore 1 integrated amp
i have now a C 2400+ P450 i think it is time to change the P450 for something betters ore a integrated one
my speakers are Dynaudio S3.4 with kimber kable 12 tc.
xlr kable also kimber

nick1