Unfortunately, the VNC protocol (which alot of screen sharing services are built off of) does not have the capability to do audio.
I, like you, often don't want to drive ALL the way to work just to do a very nominal task.
So, I'm on a mac, and typically I need to log into a mac so I use 'screens'
Since you're going from PC to Mac, I would take a look at the Google Chrome browser extension you can get and of course, test it out.
You might be making it more complicated than you need to - If you don't need a fast refresh rate try Teamviewer - it's free for personal use.
Screens has also gotten a lot of praise though it does not look free- http://edovia.com/screens/#ios
If you wanna do the opposite - mirror your iPad to iMac - try air server or reflector.
Another great solution that I am trying out as well is the product called "Screens" from Edovia. What I like is they have an app called "Screens Connect" that runs all the time and wakes up the remote and such. It also keeps the other remote systems synced up when addresses changes.
I use Screens (https://itunes.apple.com/us/app/screens-vnc-access-your-computer/id655890150?mt=8). Very simple Set up, your Mac needs to be awake in-order to access it remotely.
Learn more about it here: http://edovia.com/screens/
Splashtop is technically brilliant, and otherwise godawful.
It's really fast, meaning you can actually play some computer games on your tablet. The UI, and overall experience of installing it and using it, however, could kill a honest man in a matter of minutes. It's that bad.
Unless you want to do things with fast-moving visuals (playing games, watching movies) and have a solid stomach, I recommend a more standard VNC app, like Edovia's very elegant Screens.