Atmasphere M-60 amps used (around $2500 +/-) in conjunction with Autoformer Zeros (new for $950). This combination will give you sound quality you will not believe. Throw in an Atmasphere MP-3 preamp ($2500 used), and you will get sound that is quite difficult to comprehend vs. your old McCormick (combines with whatever preamp you were using).
Currently, I am running a pair of Vienna Accoustic Mahlers (which are a proverbial bitch to drive) with the Atmasphere M-60 amps and the MP-3 preamp and the Autoformer Zeros, and it is the finest quality of sound I have gotten out of them. Now granted, bass is not quite as good as some of the best solid state amps I have used, but my bass perfomance is still remarkable. I NEVER imagined little 60wpc tubes could do this kind of job driving the Mahlers.
Why go with Atmasphere? Because they (the Atmasphere amps) are OTL amps (transformerless), they distort the signal less than any transformer based tube amp.
One caveat though... you will most certainly need to use the Autoformer Zeros to drive your VR-4 speakers. The Zeros raise the impedance level that the amps see by either *2, *3, or *4 depending on how you configure the Zeros. OTL amps really like to drive 8, 16 or 32 ohm loads.
The other nice thing about Atmasphere gear is tube rolling is not required to get great sound. The stock tubes they use are not amazingly rare or astronomical in price (I am just using the stock tubes).
Anyway, I am a Glacier showroom which means I carry both Atmasphere and Autoformer Zeros. One thing about OTL amps... once you have heard them, it is very difficult to go back to anything else (especially anything resembling solid state).
Feel free to contact me if you have any questions.
Keith Forrest
Glacier showroom
Monterey (Seaside), CA
PS: I have heard the VR-4 amps being driven by a pair of the ASL Hurricanes. It sounded decent enough. However, I have also heard them driven by the Rogue Zeus tube moster amp, and that combination I thought was better than the ASL Hurricanes. For shear power, the Rogue Zeus is a MONSTER amp. However, if you want to best sound quality possible for under $5k, I'd go with the Atmasphere gear hands down.