I'd certainly avoid a diesel unless I was doing 20,000 miles a year or more. They're just too complicated now and they're going to get worse in September when manufacturers have to start building to the new "Euro 6" requirements. That's everything you always hated about DPFs PLUS ANOTHER set of equipment for reducing oxides of nitrogen!
Cars with DPFs don't so much need "fast" runs to regenerate them. They need about 15-20 minutes at LIGHT (but constant) throttle openings to make sure the mixture is weak and they don't slow to idle (exhaust cools down) or accelerate hard (produce more soot). Typically, anything over a constant 40 is sufficient.