Hi Kip,
Not sure of your budget....If no budget, yes, get the Jantzen superior z in a 12mfd and a 6.8mfd.....
If budget is an issue, take a look at Solen PPE caps... the other Solens are ok too, but I clearly Prefer the PPE, then get a Russian K71 polystyrene from Ebay.... this combination is very satisfying after a good break in...I have used the Solen, the K71 and Jantzen's all 3 paralleled together with very good results....
The K71 is very limited in its size availability.... they come in 1.0mfd.... 1.5mfd..... 5mfd and 10mfd. You could use 10mfd of the styrenes and 12mics of another cap with very good results... I don't care for ANY of the other Russian caps on speakers.
There are certainly other good caps, but these are all very high bang for the buck, Tim