I'm a firm believer in a ratio theory over absolute lengths, as in the ratio of trailer length (actually trailer axle to towball) to tow vehicle wheelbase length (I suppose I should include a variable for rear axle overhang for the tow vehicle as well). I believe this(these) ratio(s) is/are more important than the individual vehicle lengths.
I have a 3/4 Ton (standard Wheel base) Chevy Van that I pull my 31' Excella with, and using the Ratio theory, I believe my tow vehicle would be very close to the bottom limit of acceptable wheelbase.
Now I haven't figured out yet what the optimum ratio is, but I'm sure someone will chime in on the subject.
Nice Vehicle you have there (I always thought Land Rovers were the way to go), too expensive for my tastes.
Now since you only like to work on vehicles with bonnets, does this preclude swapping motors and transmissions from those other nasty vehicles into a bonnet wearing version? :-)
bobb