sonier
First off you are doing one thing right you are attending a very good gunsmith school.
But you aren't going to get the experience you need to open a gun shop and be successful with out a lot more than a degree. As was said earlier you must have a very good understanding of sound business practices, to make the big bucks as a builder you need time, to build up a name for yourself. I would suggest finding someone in the trade with a good name and apprentice with them. I have been a gunsmith for many years and made a very good living at it, But it isn't a 9 to 5 job, if you want it to be successful you will have to put in many more hours than anyone working for you.
When we have someone applying for a gunsmith apprenticeship we always let them know "the amount of time you will spend in study and on the job training can put a stress on you not only physically and mentally but on any relationships you might have, it is important you understand this and prepare yourself for this stress." this is true with any small business.
Buy a lathe with a large enough hole thru the spindle to get a barrel blank through. Mine has a 2 1/2 hole I also have a collet set up, and a taper attachment. I like older lathes with a lot of weight for rigidity. Although I just saw a new Accra lathe and mill that were very nice machines. As to the mill a Bridgeport style with a power chuck and power to the bed in both X & Y axis, and both the lathe and mill should have a DRO. With hand tools buy the best you can afford cheap tools means cheap work.
I read about the need for CNC machines for gunsmithing and I wonder how I made it through thirty years without one. They are not necessary for 99.99999 percent of the trade. If you are going to make complete guns including actions yes, or if you are going to make a lot of parts yes but for most if not all gunsmith work they are not necessary.
Their are a lot of things to consider when opening a shop, training, tools, location, insurance, shop set up, lighting, alarms, stock, clientele, advertising, etc...
But I will tell you this its well worth it, and if you do it right you will be happier working in the trade than you can imagine
Their are some good articles at
http://thegunsmiths.com/phpBB2/ on starting a gunshop. Also check out
www.taogart.org