Adam's plowing already gave you a good answer on what type of plow. A lot really depends on dealer support, but if you stay with a commercial type plow you'll at least have a good start.
(This is something I had been working on. You might find some of it useful.)
Things to consider in starting a snowplowing business (besides pricing).
1. Do I have the time to commit to plowing? If you are unavailable during particular times of the day or periods of time, you’ll be severely limited in the types of accounts you can take on.
2. What equipment do I have now? What will I purchase/lease before beginning to plow? If you only have a pickup and plow, you won’t want to go after accounts that need salting. If you have a ¾ ton pickup with an 8’ blade and a tailgate spreader, you won’t go after a 50 acre mall.
3. What is my market area? The closer together the accounts and closer to your business office (likely your home), the better.
4. What type of accounts will I pursue? Residential? Commercial? Industrial? Each will affect several things including type of insurance and equipment needed.
5. Do I have the expertise and equipment for this type of account? (obviously you’re asking this when you look over a proposed job).
6. For any particular job, you will need to consider - How am I going to approach this job, where am I going to push/stack the snow and will there be enough room for future pushes? What is going to be affected by where I plan to pile snow? Will I need to have snow removed from the site? You need to have the equipment for snow removal or arrange for it.
7. A big consideration: How am I going to handle the inevitable equipment failure? Do you have friends you can call on to fill in for you? Do you have backup equipment? How about if you’re sick and can’t get out? This is a real problem - even people using brand new equipment can tell you stories of how their $35,000 brand new truck bit the dust and spent the next week in the shop. In the meantime, they missed out on thousands of dollars because they didn’t have a backup truck.
8. Do I have the required insurance for the type of accounts I’m pursuing?
This is just a partial list. I’m sure others can chime in, also. Notice I have not even mentioned looking at how much to charge. Another good resource would be to develop a Business Plan. For an example of that, visit the Small Business Administration web site.