The 250k tone pot will work. A 500k tone pot may be a tiny bit brighter. The higher value is recommendable because if you turn it down to 9, it's basically a 250k pot - in a guitar circuit the tone pot is wired as a variable resistor, not as voltage divider like volume pots.
I would try the pickups with the existing pots first. You can always replace the pots later.
Cheers Stephan