there is an 8mb gm bank here
http://members.lycos.co.uk/darrellnet/samples.htm
that is free and very good
i would avoid trying to buy the non free ones here, the guy is a jerk and the downloads are windows only
if you feel like using a bigger one my favorite is
http://www.personalcopy.com/home.htm
on the left click on soundfonts for linux
and download the one labled PersonalCopy 5.1f
it has an absolutely killer piano
beyond belief.
happy tunes