Resquest for new GTypes and some Help

[Daniel Espinosa <esodan gmail com>]

I'm trying to have working GDA in GTK#, and at the moment I'm trying
to port GdaValue from an union structure, to use GValue as container.

But GValue need GType derived types, and GdaValue need to store the
following types:

GList
gshort
gushort

Thist types don't exist as GType fundamental, to use in GValue; could
any tell me how can I implement this types as part of the gda library
or may this task is better to have this GTypes as part of GLib.

Other Help fast, is it better to derive a struct from G_TYPE_BOXED
enstead from GObject?