If you need a suitable SSD or HDD for the upgrade we recommend the SSD wrk for Mac by Angelbird made in Austria. This professional SSD with native TRIM-support Out-Of-The-Box is available in sizes 128 GB , 256 GB and 512 GB and can be ordered directly through our website.
You can also order our SATA3 adapter kit together with the SSD wrk for Mac and save up to 19,90 €: hardwrk SATA3 Adapter SSD Bundle
Since the SATA2 standard is outdated and SATA2 SSDs have become pricy we do only recommend SATA3 SSDs. They are working in every MacBook (Pro). The Samsung 840 series has been replaced with the EVO series which achieves even higher write rates as their predecessor. Furthermore the EVO is the first SSD to provide 1 TB capacity at a reasonable price. Yet the EVO is a bit more expensive than the 840 series it still is our recommendation. Even faster, but more pricy as well is the 840 Pro series by Samsung.
For the use in your MacBook (Pro) we recommend the silent HDDs by Hitachi (500GB/750GB) which Apple also often places in their MacBooks. If this is not enough space for you, pick up a Samsung or WD disk providing up to 1 GB of space. Keep in mind though, that in most cases more space also often means a louder and more energy consuming drive. So you should think twice if you really need an 1 TB disk in your MacBook (Pro). We strongly advise against the by now available disks with 1,5 TB capacity.
Our tip: Better go for a disk with 750 GB and 5.200 RPM than for a 1 TB disk with 7.200 RPM. The difference is not that much in an SSD/HDD combo and in most use cases not relevant.