Hey Keith,
I've read this whole thread and I'm going to try to actually give you advise based off what you asked. For some reason almost no body wants to do that, it looks like most everyone here just wants to complain about their situation, not yours.
I have a very similar situation to yours. I am a veteran, I have a credit score over 800, I have a full time job, I started a tree company within the last year.
That being said, we have some differences too. I have a few years of climbing experience with a very good tree care company that focused on being an arborist, not a log humper. They sent me to a climbing school, and since I left that company I have climbed recreationally since for about 7 years. I am no master but I am comfortable and am aware of what my limits are. I also have experience (the last 7 years) working at a dealership for outdoor power so I know how to fix saws and engines, how to properly run and maintain them.
So when I started my business I did it with a partner. He doesn't have experience or financial backing BUT he is a hard worker and it allowed me to have someone else to share the load. PLUS you really do need someone else to do tree work, just from a safety aspect but also a practical stand point.
We didn't have a lot of money either, far less than you in fact. The first step for us was getting incorporated. From there we opened a bank account and then got insurance. Bingo bango, we were in business. We already had saws and climbing equipment (which it sounds like you have as well) so everything else outside of that is just there to make it easier for you, NOT requirements. So guys who say $100,000 to start simply have no perspective of BUILDING a business.
We did the jobs that we knew we could handle with the equipment and experience we had. And we worked hard. If someone had three pin oaks next to their house, 90 feet tall leaning over the house... guess what, we said no. We took the small jobs, saved up more money. We also market ourselves as expert pruners and a tree CARE company, not Joe-Shmo with a Ford Ranger and chainsaw. My experience was in formative and structural pruning. I stay up to date on the best practices and techniques for what is best for the tree. That being said, of course we do removals but it's not our primary area of expertise so we often price ourselves out of jobs. If the person says no, great, we aren't looking to do that kind of work anyway. If they say yes, great, we priced it so it was well worth our time. Maybe this type of business model isn't for you but our area has many tree-conscience people so we can.
So we got a number of jobs under out belt, got great experience and banked what we made. The key to our scenario and to your scenario that everyone on here seems to be ignoring is that you and I are NOT relying on the tree company as a living. We both have successful careers. This allows us to build the company over time, as long as you have patience.
So, all that being said we found that outside of the obvious stuff (saws, ropes, climbing gear, etc.) the next most important thing was a chipper and then in turn a truck to pull said chipper. We are a small outfit, we don't need the biggest, baddest, newest stuff. We found a couple local auctions that sell these things used. So we got a solid chipper and truck to make our jobs easier and it allows us to more competitively quote. These set us back about 12K. We went with a regular dump truck too because it does what we need and is cheaper and more available than a chip truck or bucket truck.
We do on average 3 jobs a month and make at this point about 3k per month. As a side business that is perfect. It adds some to what we already make and it's not so much work that we are killing ourselves.
I agree with Danceswithtrees about education. In your free time, research tree care. You want to show up at a job well informed of what you are looking at. And all the marketing stuff, sure that is great and I am well versed in it but you are going to get a ton of work from word of mouth. Show up on time, presentable and do good work. Word will travel quickly. That will get you further quicker than any SEO techniques or Yelp reviews (again, not saying those aren't important but you are just starting out).
I feel bad for you that a lot of people on here are bashing you. It sounds like you are doing this in the smartest way possible and you are researching before you make the plunge. How can anyone knock you for that? I commend you and wish you the best. If you ever need any REAL advise, reach out to me I am always happy to help a fellow tree care specialist and veteran.