Have one or both of them fitted as slider, it's very handy in warm weather as it improves the dash vent air-flow hugely when opened and saves most of the noise and buffetting that you get from the open cab window/s.

Also have them tinted this provides some protection for any contents accidentally left on view, plus you can still see out at oblique junction which I assume is the reason for fitting them...

Don't forget to make a decent job of rustproofing the cut metal otherwise your door tin will disolve faster than sugar in a hot drink.

Look in Yellow Pages for Commercial Vehicle body building suppliers to pusue your dream that bit further...