We use Mac valves so my answer would be neither. They all make quality products though... We use the 24 VDC version because the availability is generally better. (At least for us) I don't think the 12 volt version is the root of your problem though. We also use the DIN plug version which allows a slightly beefier wire. The first time I ever used 18 gage wire & beefy in the same sentence.
