If the cost per mile is any consideration you need to keep in mind that with diesel running 30-60ȼ more per gallon than gasoline, the difference in fuel milage will not offset the additional cost of fuel. Having owned both diesel and gasoline vehicles, I assure you that most owners find that the diesel maintenance costs more as well.
As Chalkie points out, some diesels are noisier than others, and the same goes for gasoline engines. That carries over to the bigger diesels in diesel pushers and hdt's as well.
So, take a ride in a few and see what falls within your tolerance threshold.
Personally, unless you're putting a lot of miles on, I'd opt for a gas motor, both for upfront price and normal maintenance.
I do not have a Class C, I do however have a diesel pickup and I can say that it is no noisier than my son's gas pickup. Outside it seems to me that the Ford and GM diesel engines are quieter than the RAM Cummins engine. One thing to consider in your deliberations is fuel economy. Diesel will not necessarily get better.
At a zoom meeting last night it was disclosed they found more cracks on that bridge. Nothing yet on duration of closure or plans for repairing. They're still doing more intense inspections.