Have just upgraded to a Pioneer VSX1016 and Mordant Short 90X's

An considering going to bi-wiring, or should it be more expensive 2 core
wire. want to spend around £20.00 per metre, too much? not enough? plus
banana clips, but I have never used them before, do they fit into both
amp and speaker or are they different sizes for either end? checked
manual for amp and cannot find the size of the output terminals for
plugs. also do you need to solder the clips?
One other thing, the VSX1016 has phase adjustment, so I 'think' that
means I do not have to have the same length for each of the front set,
so might save £'s there (1x1m 1x2m 1x3m)

Any recommendations on the wire? site links for reputable suppliers.
Sorry its a lot of questions.
Un.