Hi Rikki and Chony. Thanks very much for the links and samples.
I don't think I need a sampler. I just wanted to create something like a virtual P-140 with a cheaper keyboard (maybe a Privia 100?) and a laptop with controls and a couple dozen instrument sounds on it -- to start.
This is not to create a studio. It's purely to rig up a gigging keyboard and save some dough. All REAL TIME. It seeeeems to make sense, but I get the feeling home computers are still not up to the price point. They should be by now, but my theory is multi-tasking got in the way.
It's not the CPU, exactly, it's the latency when the "soft synth" (new word for me :eek

has to go on gueue to request memory from Windows. If they had just stuck to DOS ... 250 Mhz would do it, I bet!
But now that some people are actually doing this, in six or seven more years, price will come way down, and everybody will do it this way. Then you'll see professional weighted-88's without so much as a flute onboard.
Maybe somebody will come out with a dedicated Kbd/software combo to do this soon. The software would work better if it ran on Linux -- much less latency and much more stable. But that's no problem -- the installation could be on the same disks. Advantages are a nice big color display (practical scrolling scores!?) and totally expandible.
There would still have to be a few knobs and such on the kbd, though.