The sound quality is excellent, but it's a dying, if not dead format as far as mainstream releases go. In view of that, you're only likely to find limited titles of interest unless you like jazz or classical. Those releases which are more mainstream are usually secondhand and quite expensive. In that respect you'd probably be better off getting a player which does more, e.g. the Oppo BDP-831 will play DVD/Blu-Ray/DVD-Audio/SACD/CD. That way you can get a few titles, but you've got a source machine that will do a lot more.
SACD cannot be output via a SPDIF digital out, it's either got to be decoded by the source and sent to the amp with analogue outs, or sent via firewire (i-link) to a compatible amp which can decode it, or sent by HDMI as a DSD (preferred option) or PCM digital signal.