Come to think of it, this might really suit you - a Kona Paddy Wagon. It's a drop handle single speed with a tough cromolly frame. Faster than a 7.5 (unless you have a steep hill to climb), much tougher, very little to get stolen by bike strippers. It can take 32mm tyres - a little narrower than I'd like, but not bad. If you found a really clever LBS they could probably fit swap the rear wheel for one with a Nexus IGH hub and fit a JTEK shifter - you'd then have 8 gears, but covering a wider range than 8 derailer gears.
http://www.bikeradar.com/gear/catego...-wagon-06-8998