I'd go with the Jupiter copper foil caps. Once you have tried a copper foil cap it's hard to go back, but the V-Cap CuTf are too expensive, about 3x the price of Jupiter.
On the XLR thing, there are some advantages but if your source does not have a true balanced output there's no reason for it. It also requires two of everything, greatly increasing the cost of equipment. One of my customers was told the XLR inputs on the Zen are much better, but now he wants to upgrade (within the Decware line) and the amp he wants does not have balanced inputs as an option so now he spent a bunch of cash for an amp with an XLR input and and spent more on an XLR cable only to go back to single ended.
If you'll be using a SET amp and own a source that is balanced then the only good way to go from balanced to single ended is with expensive trafos ($650 option from Decware). This makes very little sense to me, if I was using a balanced source I'd want it amplified by an amp that is truly balanced as well which would mean push pull without a phase splitter... and such an amp can only take balanced inputs. Very few manufacturers make tube amps like this, Lampizator is the only one I'm aware of off the top of my head, and this is basically two SET amps run in parallel, each with one phase of the signal, and rejoined at the OPT. Or a SS amp with similar topology which is more common.
OTOH, some would say that the better CMRR of a XLR cable is worth it even if the amp is single ended but the truth is you are spending a lot of extra cash to solve a problem that doesn't exist in short IC runs in home environments 99.9% of the time. XLR was designed for long runs where interference is likely to be a problem, i.e. pro audio.
tl/dr... I think for most people it makes more sense to buy a DAC that is built with single ended outputs and use a single ended cable to connect the DAC to their single ended preamp/amp.