I like both Crucial RAM and Crucial SSDs. Maybe because that's what I own and have never had any problems with either. Some people like OWC but I find that they are overpriced for the same, or similar, products from Crucial.
Visit the Crucial website and click on the System Scanner tab. Download, unzip and run a small app that will report your model # information back to Crucial and you'll be presented with recommended upgrades for your particular model.
Note that you can sometimes find the same Crucial items for a couple of bucks cheaper on Amazon.
Good luck,
Clinton