Installing bathroom exhaust fan/light

I recently bought a house and need to install an exhaust fan in my upstairs bathroom. The fixture is not over the shower. And the lights are on a separate 15 amp circuit from the GFCI receptacle. It is currently wired like this:

14/2 power to ceiling light–> 14/3 to vanity light–> 14/2 to light switch.

My wife wants the lights wired together on one switch, but wants the exhaust fan on a separate switch. I plan on ripping the single gang box out of by bathroom wall and replacing it with a double gang. How can I best achieve this with minimal rewiring? For example, can I run separate 14/2 just from the fan portion for the switch?

The light/fan I bought has: 2 white, 1 black and 1 blue (plus ground).

I am a novice with home wiring, though I have done electrical repair on computers and electronics. Thanks for the help. Jeremy