Hi,
I recently posted a thread where I did things the other way around. I bought some PMC FB1+ speakers, and eventually ended with your Primare combo.
The combo with the PMCs sound smooth and velvety. I am not sure if the PMC would give the treble you are after, at least not the FB1+. The FB1i might be, but I haven't heard these and an audition may be worthwhile.
Through swapping bits around I got the impression that the CD31 was a slightly warm soft player. I also got this impression from the What Hi-fi review. Given that What Hi-fi were spot on about the smooth nature using RCA plugs, they may be spot on about an improvement using XLR balanced cables. They said these would give a bit more lift to the sound.
Have you thought about trying these as an upgrade, if not using using now. They may be a lot cheaper than new speakers. I have been quoted between £130 and £500 for these. It was a good job I was leaning abgainst the counter at the time, as I would have fallen over.
I have started researching on the web, and the sound pros seem to think that cheaper cables may be just as good, as this cable seems to be a stable item for the recording industry. I might start cheap, as I have nothing to lose.
Could you ressurect this thread if you get some speakers, because it would be interesting to see what the alternatives to my PMCs would have sounded like, and good luck in your search.