you could try the Donald Trump collection he seems to be a solid color tie kind of guy
I don't go for the solid ties much but I can understand why you need them
random suggestions:
comb winners and hope for the best
head downtown where you can find all of Harry Rosen, Holt Renfrew, Grafton, Sears and several other clothing stores...probably highest density of places selling ties, although some of these places will be $$
have you considered the formal wear/tuxedo rental places? if you truly need it only for one day?