Personally, I'd look at the X200's instead, and spend a ittle more on the speakers if this whole system is going to be long term. This will allow you to look at speakers in the £3.5k range rather than £2k, giving you a speaker far more in line with the system.
We have a huge Cyrus database of customers, and although there is a huge range of different speakers being used with Cyrus, there are one or two favourites. The biggest favourite is ProAc. In this case look at the Response D28, which produces a nice sweet sound with a pretty potent bass. Many people like them because they tend to reproduce most types of music, however badly produced, in a presentable way.
Secondly is KEF Reference. You could just about squeeze the Reference 203/2's, which are more accurate and precise than the D28's, producing a more even response across the whole frequency range. They're a little more upfront and attacking than ProAcs too.
Many people have chosen Spendor too. These are some of the smoothest speakers available, which some people like with the forward sounding Cyrus. Some like them as they tend to be less demanding regarding positioning. Try the A9's, which are an initially unimpressive speaker, but their qualities tend to shine through after a longer listening period.
PMC are also a popular choice, more by those who like the KEF sound, which is a little more direct. The PMC's have an energetic treble which produces plenty of detail in a very lively way, which is excellent for lower level listening. Try he OB1i's.
We did used to keep many Dynaudio products, but there are a few ranges that have just been hiked up too much, taking them out of contention when compared to more competitively priced products.
If you stick to the X300's, you'd need to look at the ProAc Response D18's, KEF XQ40's, Spendor A6's, and PMC GB1i's, which really won't be doing justice to such a revealing and detailed system.
You could always go ahead and get the X300 system, and pick up a bargain pair of floorstanders temporarily, and save up for better speakers further down the line?