One word on 6 track tape sets. For them to work cleanly, it is important to have the headblock azimuth aligned as you will be hearing two adjacent tracks at any one time. If the heads are out of alignment this will cause sonic hell. A sort of phasey soup. This isn't a sales plug, just to alert anyone thinking of track tapes that a potential problem exists. You should all have your headblocks aligned anyway but definitely if you are going the 6 track route.
Best,
Martin