if i recall correctly you are planing on using the energy you harvest for heating.
that's what i want to do as well.
everything i've read about it says you need to run a higher voltage to be efficient.
using all the poles per phase, like you are talking about, should give you that.
because you are using 20 coils to get the voltage you want, it should be possible to use a heavier conductor and reduce the resistance.
i think its a good idea to use the mags you have for this smaller one.
i can tell you one thing from experience .
they sure don't make much power sitting on the shelf.!!
lol