Modifying Philharmonic 3 crossovers


Hi, everyone I'm new to modding so I'm going to need a bit of help. I have a pair of Philharmonic 3 speakers and I see that they have Claritycap PX capacitors and I'd like to  change them out with Claritycap's new CMR line up although I'm not sure how to start. I see that two of the capacitors are rated at 20uf & 250Vdc although there aren't any CMR caps that are rated at 20uf only 18 and 22uf and 400Vdc. I'd like to upgrade the capacitors although I'm not sure how I would proceed. I would very much appreciate advice on this topic. Thanks!
128x128jonny1080
Have you spoken to Dennis? If you are in DC area, you could even take it back to him. He is a great guy. 
Ask your electronic parts vendor to measure either the 18 or 22 uF caps closest to your 20 uF you are looking to replace. Capacitors can have a 10% value tolerance and I am pretty sure that you will be in position to find the requested value. I know that PartsConnexion is able to measure capacitors to your requirements. They are also a Clarity distributor.
Thanks for your advice dasign! I was also wondering about the various voltages of the claritycap capasitors. Does the voltage make a difference?