Don't bother with specific "audio" caps.... they're just decent quality regular ones with a fancy name and a jacked up pricetag. If you want premium caps, look for higher voltage rating, higher temperature rating, lower ESR, etc.... nothing about "audio grade" caps make them inherently superior to other good grades from good brands for any sort of audio work.
There's also nothing wrong with going with higher voltage ratings, so if you can't find a 63V like the original, anything larger will still do (though they usually get physically larger and more expensive). There's also the option of putting several caps in parallel - While still only with substantial solder tabs, it gives you some flexibility in wiring options and trying to fit differently sized caps somewhere in the existing chassis. If you find something that fits your form factor that's a higher capacitance, that would also be a fine option - something of this size is not going to be picked for a really specific value, they just wanted as big as was easy to get to be a big reservoir of power on demand, so while a lot less is probably bad, a little less - even 20% or so - is probably not a problem, and any amount more is fine too.
Oh and if it wasn't clear, there are caps of that size that have solder terminals - a quick search at digikey showed several options that would work. Then there's also the screw terminal type, the older axial style, then stuff that's better suited to spade lug connections and the like.