Smartboards are like Apple computers.
(You obviously don't have a lot of experience with OS X.)
If you want to tinker [...] Surface Pro 2 [...]
[interactive whiteboards] are about as useful in a classroom as an iPad
Yeah... right... So, in your opinion, the superior solution is a Surface Pro? Really?!
You can totally use even an iPad, load it up with the right apps and hook it up to a projector to achieve the same or an even better experience than you are describing, like with almost any other device.
What would actually be an improvement is something like a Wacom Cintiq (or their much cheaper predecessors) to give you more control over your drawing, but what platform you use (Linux/Windows/Mac) matters only inasmuch as you should feel comfortable with it.
Incidentally, the interface that gets out of the way and let's you get stuff done the most is (a well configured) Linux and/or Mac.