Both are good RAM -- if you get the models that they specifically guarantee for your model Mac. I don't recommend going with the generic Kingston ValueRAM (KVR-Series) for a Macintosh.
If you are in the USA, there are other reputable sellers that are often reocmmended by MR readers, OWC and
Data Memory Systems, which you may find more reasonable in price.
Thanks
Trevor
CanadaRAM.com