One small point to offer, generally speaking, I would check the underside - chassis, engine compartment etc. for excessive rust and corrosion. Especially on the moveable parts of the front end - steering linkages and such. They all have grease fittings and you should be able to tell if they had been kept greased. Of course, check around for any leaks or fluid weepings, especially back around the engine. As others had mentioned, take a look at hoses and belts and such for excessive deterioration.
If you were to buy this rig, it would be a good idea to start with all fresh filters and maybe belts at least. You might consider replacing the air cleaner/filter and if it has air brakes, a new dessicant filter on the air system. An oil change as well. Sure, it will be a few bucks up front, but then you will at least have a benchmark as to when those common maintenance items were changed, and you would be able to set up your maintenance intervals from that.
With regard to insurance, that is pretty wide field to choose from. We've personally had good luck with Progressive. For us, in our area, they were the most reasonably price for comparable coverage with the other providers. However, based on your geographic area, your findings may be different. That's something that you would have to shop around to find out.