Software RAID or a host-based controller is the way to go with SSDs. Otherwise the raid controller becomes your bottleneck as whatever onboard ASIC or RAID-on-a-chip hits its throughput limit (and potentially overheats and dies if it's some crappy product designed for HDDs).
TRIM is well supported by modern host-based controllers designed for SSDs.
TRIM is well supported by modern host-based controllers designed for SSDs.