I would recommend that before you start changing major components, you should try some high quality silver interconnects. They have a tendency to be more revealing at the high end than copper. Some cables I would recommend are the Kimber Select 1030 (expensive), Silver Audio Silver Bullet 4.0, or the Harmonic Technology Pro-Silway Mk II (combination silver/copper). Many people on Audiogon have also recommended Acoustic Zen silver cables, but I have never tried them. Although I use silver interconnects, I have copper speaker cables from Kimber, and the combination works very well.
Audio Research makes great amplifiers, and I'm not so sure that changing your VT-60 to the VT-100 will get you the added detail you are looking for. A speaker change might give you better performance. I have heard the Vandersteens extensively, and while they are very good, I much prefer the PSB Stratus Gold i's, which can be found used for less than $1500 here on Audiogon. My point is that I think you can get the results you are looking for by spending less and without having to blow your remaining budget on a cd player change.
Audio Research makes great amplifiers, and I'm not so sure that changing your VT-60 to the VT-100 will get you the added detail you are looking for. A speaker change might give you better performance. I have heard the Vandersteens extensively, and while they are very good, I much prefer the PSB Stratus Gold i's, which can be found used for less than $1500 here on Audiogon. My point is that I think you can get the results you are looking for by spending less and without having to blow your remaining budget on a cd player change.