No, it does not support TRIM. Currently the only drivers supporting TRIM are Microsoft's own storage drivers, Intel's, and AMD's.
And only selected controllers support TRIMing an SSD that is in a RAID array.
While the C300 drives are very fast, the build in garbage collection is not very aggressive, so without TRIM you will get a significant drop in write performance. I would recommend that, rather than running them in a RAID 0 you have them separate and spread out the IO load by installing stuff to both of 'em. This would allow you to use Microsoft's own drivers and so get TRIM.