Citaat:

. I to worry that with one of the other units I'll look like Mr.Ed counting with my foot.





If you don't want to use MIDI you'll have to trigger the harmoniser yourself in some way. Be it with your foot or with your hands. Playing guitar you'll probably use both hands...

If you work with a laptop running RB, you might even want to try a software harmoniser. I haven't used the TC harmoniser supplied by PG Music, but I'm sure you can do some testing with that one before you decide to go hard- or software with this.
I'm not sure if you can do automation in RB, but that would be ideal to manage the harmoniser.