What about an equivalent IPad and app? Maybe something like (https://itunes.apple.com/us/app/baiboard-collaborative-white...) (I haven't personally used it but ipad's would make more sense in the Apple world ...)

Looks like there are a few other options:

https://itunes.apple.com/us/app/groupboard-collaborative-whi...

https://syncpadapp.com/

Tablets can be slightly cheaper than houses near the office.

ah yeah, I actually use a macbook and surface pro 2 at the same time as pictured: (http://imgur.com/a/fqf3P) combined specs are actually similar to a new mb pro (combined 512 gb ssd, 16 gb ram, ~4.7 pounds), and cost is less, given that the sp2 was bought used so total ~ $1900.