Clansing1, how much time do you have, is money more important or time? I've done work like that before and the chains and saws are really high priced, a couple of sawzalls are cheap along with a concrete saw with either a metal blade or carbide blade depending on what material you have to cut. Most roofs are just wood and nails and some occasional metal, a sawzall isn't fast but you can buy several with several guys running them and all the blades for a fraction of the cost of just the demo chain, and those are carbide tipped and expensive to sharpen as well. Use the sawzalls and concrete saw along with a regular chain saw and sledge hammer, most of the cutting you'll have to do is through wood and if you look carefully 90% of what needs cutting can be done with a regular chain on a basic saw, just look for nails before cutting and cut around them or almost through the wood and then cut with either the cement saw or sawzall.
Depending on what type of roof is on the house will determine how to go about it, if it has a metal roof thats what the cement saw with metal blade is for and if it has a shingle roof, we pound them off from inside to make a hole to stand up in and either chainsaw or sawzall off the 2x's for roof supports, once you figure out how long some of the nails are most will be about the same length though out the whole roof.
If speed is more important go with the demo saw and carbide chain route but you can buy all the other tools and accessories for less money than just a couple of chains and then you have the other stuff for other jobs as well.
