If you are going to Jaycar you could also get yourself a rotary switch (1 pole and X positions, ~ $4) and wire up a test circuit with the rotary as your cap selector. Then just switch back and forth through the caps to find the one(s) you like. Wiring a Jnr with 2 push/pulls would then allow you to bypass your tone circuit with one push/pull and select between two caps with the other.
Or, if you're happy with just one tone cap, you could always skip the push/pulls and just use a No Load pot for your tone control... that gives you bypass at full clockwise without an actual switch.
This may also help: Multi-part video testing and evaluating guitar caps (and uses P90's in the test)