Modifying it might reduce its resale value, but if you intend to keep it for awhile you will be pleasantly surprised by the improvement after replacing the stock REL caps and also the Wima filtering caps on the power rails. I did this to an old ARC PH2 and was amazed. I was going to sell it for beans, but after modifications it has become my MM phono stage of choice.
For this application I wouldn't stretch for V-Caps. Infinicap is now Dynamicap-- which at least offers the consistency of being ARC's current cap supplier. Or try MIT PPFXS or ClarityCap MR or ESA.
Dave
ClarityCap OEM Sales