Similar to HDD, SSDs also
Similar to HDD, SSDs also have issues. From my experience, they either work without issue or don’t work. I have the 96GB Kingston V+100 in addition to a G. Skill Phoenix Pro 120GB and an OCZ Vertex 2 120GB. I have had no issues whatsoever with the Kingston or the G. Skill. I had to RMA twice the OCZ in order to get one that worked without issue. Even Intel has had issues with their 320 model that you are looking at.
In general, I expect SSD to have a much more reliable and longer lifespan than HDD though there isn’t a whole lot of hard evidence yet since commercial markets have just started using SSDs in increasing numbers. They are just NAND “Flash” memory which has been around for a long time and is in many products both in consumer and commercial markets. There are sometimes issues that have cropped up with SSDs though in practice, it seems no different than HDD issues we have seen and manufacturers do seem to be responsive in correcting issues either by issuing new firmware or replacing the drives. Whether you go for SSD or HDD, backup and be safe. Always expect the next failure.
Also, contrary to much of what you might read or hear about having to “tune” for SSDs, if you’re running Windows 7, there’s not much that really has to be done. If you install Win7 on the SSD from the start (make sure drive has latest firmware), it should recognize the drive as an SSD, enable TRIM, turn off defrag, etc. (run WEI and check if you want to be sure). With any modern SSD and Win7 it’s not necessary to disable page file, move a bunch of OS stuff off the SSD, etc.
Your AVerMedia M780 is a low-profile card according to the linked datasheet. You’ll just need to dig out the bracket that came with it.