Here's one more option for you to consider -- keep your Cambridge 540 and get a good DAC. I really enjoy the sound of my Benchmark DAC -- in my system, better than both the Rega Apollo and the Cambridge 840C.
I second this suggestion. A transport with moving parts can fail - so why plough more money into it - besides the DAC1 has a USB version now and it looks like PC server music is eventually going to replace CD's anyway - in that sense a DAC may serve you better for longer. There are other choices of DAC each with a slightly subtle difference in flavor - however just ensure you get a DAC with highly respected interface jitter reduction capabilities and you can pretty much take the "transport" piece out of the equation.