@Ricardo M. I don't think you necessarily need a certain amount of funds to sit down with a HML. Rather, I think the discussion with the HML will help you determine how much money you actually need. If they are going to fund the deal based on ARV, you might not need anything up front if you find a good enough deal. In fact, you may find that you can fund some of the rehab through the HML in this scenario. However, I have personally found this type of funding to be hard to find, especially for a newbie. Once you talk with a few lenders you will find out what will work best for your plan and determine how much you will actually need in cash.
About the number of flips, I think it's okay to push yourself towards 4 flips in year 1 in your business plan. I am a supporter of stretch goals and "aiming high", I just like to stay pretty conservative when I am analyzing a deal. Think about it this way, if you project profit assuming a project timeline of 6 months and you complete it in 3, that is just more $ in your pocket. However, if you project the profit using a 3 month timeline, and it actually takes you 6, you could run into some cash flow issues, especially under a tight budget. Just in interest alone, assuming a 12% interest only loan from a HML you are paying $1,000/month on a $100,000 loan. If your project runs over by 3 months that is an extra $3,000 in cash outflow, which represents 15% of your overall budget. Just something to think about.