Capacitor

Good for you! Why would you change the values? Keep them as now! Higher voltage ok, no to impedance change.

I am not changing the value currently they have 0.33 uf was asking which brand to go with as there are 18 caps to change

@grannyring 
what is your thought on miflex KPCU caps

I like Vcap Odam much more than Miflex . Just pulled out Miflex and replaced with Odam in my amp. Much better after break in. Everything improved from bass to highs.  More depth, more inner detail…..you get it. 
Miflex are forward sounding and not as smooth and detailed as Odams. Odams are even better sounding than Jupiter copper in my experience, but I shared this already. 

I understand what you say, but then 18pcs of Odam 0.33uf 600VDC is some big money and miflex is less than half the price of Odam