CD player upgrade for Solo amplifier?

Hi, I didn't know which section to post this in, but seeing as 95% of my listening is now through 'phones I thought I'd post in this section.

I've just upgraded to a Solo SRGII and HD650s to go with my Marantz CD6002.  While this setup gives me a beautifully rich, warm and musical sound, I can't help but think that the head amp and 'phones are capable of more with a better CD player.  I've got a very short list of Marantz SA8003 and Naim CD5i at the moment.

Does anyone have any other suggestions for players that I should audition?  I like a rich but musical sound with full bodied vocals and a nice warmish but detailed midrange.

Thanks, Mark.