MIDI has fallen out of favor since mp3s have gotten popular, so modern cards pay less attention to midi quality and have a lag for live performance since they are done in software.
A software player solution is availiable called Wingroove. It is an old shareware program with limited instruments, but very good sound for the ones it supports.
For live performance or playback the old Wavetable Daughter cards; Yamaha DB50 or Roland SC-15 are hard to beat. I know the TBSC supports a Wavetable card. These would be hard to find unless you get them used.(? ebay?) If you get a Wavetable card , it can be a synthesizer on a card, giving 400 to 600 instruments.
Jim