Lo Ady,
as far as source material for the HD edit goes... Are you going to wait for an 'official' HD release of Ep 5 or use the cable/satellite rips that are out there at the moment?
I can get hold of the PAL Wookie Groomer v2 WMV-HD VC1 edit which was from a 1080p H.264 source, but to be honest the definition of the picture didn't blow be away. It might just be my eyes but the difference certainly wasn't night and day, as it is with HD versions of other movies compared to their DVD counterparts.
Might also be able to get an x264 version so let me know if I can help.