If you can get 128MB working, you should also be able to run Xubuntu, although many criticise it for having lost its way somewhat and being too dependent on GNOME libraries. I rather like it, actually.

another alternative would be Fluxbuntu, or some other distro that uses a very lightweight window manager like Fluxbox, and is optimised for older hardware. I understand that distros which use the older 2.4 Linux kernel have broader support for older hardware.