Are you intending to spool audio from the SSD?
Will the SSD be the only drive? Bear in mind it's generally considered a good idea to use one drive for the operating system and software and at least one other to record to.
For audio recording/playing a fast sequential read/write performance is a good thing. For OS and software a drive with very low seek times might well perform better because OS and applications tend to be relatively small and are quick to load.
In the real world SSDs are pretty good at both sequential data handling and have very low seek times and the differences between them aren't always that great. I use an Intel 520 series as the audio drive and it easily handles everything I throw at it.
One thing to consider is that an MLC SSD may well outlive cheaper SLC varieties because it will (should) take much longer to "wear out" as a consequence of repeated delete and write operations. Though SLC SSD lifespans are way longer than the pessimistic views that were around when they were launched. And an SSD that is directly attached to the PCI bus will probably out-perform a SATA drive, though again the difference may not matter much in the "real world".
And if you are considering more than one drive don't use a USB SSD - the USB specification doesn't allow the OS to pass TRIM commands to a USB-connected drive. So make sure SSDs are hung off the SATA/PCI bus or are eSATA or Thunderbolt if external.
In short, just pick a model that's a reputation for reliabilty and decent speed figures. Don't get too hung up on minute differences, picking between them can be like reducing a DAW's round-trip latency from 5ms to 3. It looks like a big improvement, and in percentage terms it is, but in use you'll never notice the difference.