You don't need 1GB of RAM free to run the large Gigasound piano samples
in LinuxSampler -- it caches some of the sound data, but leaves the rest
on disk and accesses it only as required. I'm not sure exactly how much
RAM you'd require to run it (though LinuxSampler with the Maestro patch
loaded uses about 180MB on my system, FWIW), but it should definitely
work on a system with a total of 1GB of RAM.