Sadly, Cambridge equipment does not yet include any room equalization capability. External EQ can be quite expensive.
You'll pay at least a 50% premium for pre/pro + amps with the same capabilities and quality as a good AVR like the 4311. Still, there are reasons other than just audio quality for getting separates. You'll have to decide if they matter to you. Many people like the Integra DTC 80.3 pre/pro, for example, which can be quite effective when teamed with Emotiva (or your other favorite) amps.
Don't forget that you should be spending at least 2/3 of your budget on quality speakers.
Marantz SR7009/7.1.4/FH+TM/DefTech PM1000/LCR+TM amped