I noticed 3 out of 4 modules I'm getting have I2C pullup resistors on the breakout board (10k), will they still work when I need to add another 4.7k for the module without pullups (K30)?
No, you'll have to remove the pull-ups from the breakout boards. As the K30 doesn't have an I2C interface you should be able to run all sensors on 3.3V. Depending on the type of Arduino you're going to use you might have to modify some libraries. And for the 3.3V pull-ups you should use 3.3kΩ resistors with that many sensors. Keep in mind that the complete I2C bus length shouldn't exceed 50cm, the shorter the better.