the only 25 that comes to mind that'll fit in your space (with a little modification) is the hantarex mtc 25 ev/2.  to make it work - you would have to bend the side and top mount ears back - and make a shelf that the monitor sits on (there are bottom mounting slits  
but.....
if you live in the states - this badboy will have to be shipped from sambers in italy.  the journey is ROUGH on the monitor (and their packing really isn't suitable).  mine got chipped and had a bent frame when it arrived.
heaven forbid you ever have to make a claim with UPS Italy - took me over 5 months to get my money....  
every other 25 i've ever seen is larger - and most likely won't fit in your cab.  i'd consider something smaller - although i do appreciate the need to have the largest monitor possible 
