PCManFM would be awesome on the IT's, and it's lighter than Emelfm2. (btw, emelfm, the original, would also be great).

And as it's a GTK app, would it be too hard to port?

edit: GTK+1 emelfm, Debian Sid armel package works on the IT's, with a few UI glitches (preference dialogues).

Like XMMS one has to start it with LC_MESSAGES=C LANG=C otherwise the dialogues' text will be empty.