Hi Urban' - yes, that photo did the rounds a while back - it was in BIKE magazine too as I recall...
The first feature I wrote for TBM was about taking that bike (and Julie on her KTM) to Morocco in 2006 - got plenty of photos there too...
The fastest car...
Is a hired car!
Ok, back to normality... if you really only want to use a trailie on the road, I would personally go for a Suzuki DRZ SM - the supermoto version... not only does it have full road-legal lights and a proper ignition key, but electric start of course, and the supermoto wheels and suspension will make it far more 'fun' if hooning around on tarmac is your thing... the nice thing about the DRZ SM is there are plenty around, mostly pretty cheap, and loads of aftermarket parts for them should you feel inclined? - Fodder on here has one in Las Vegas as his commuter bike, and it's a beast with a Yoshimura pipe on it!
Jx