Doc-Z, LiveSynth Pro and Kontakt are sample players. Kontakt is a high quality sample player often used in professional studios and live performances. LiveSynth Pro is no longer available. I used it initially so I could load a GM/GS/XG wavetable and play Yamaha styles (auto accompaniment). You could use a GM wavetable but you would need to modifiy the Yamaha styles (drums and other voices).

To play large samples you need a high quality sample player (Kontakt) and a computer with a 7200 rpm drive and a 8 mb cache. The way this works is that a small portion of each sample is loaded into memory and as you hit a note the rest of the sample is streamed from the hard drive. You need a hardware & software system with low latency (less than 10ms). I run my system at around 2 to 3ms --- not hard to do with todays computers and good sound cards.

If your objective is to get as close as possible to the live sound of acoustic instruments then this is the way to do it.