You are a small group but I feel better about the way you describe your self (as if you needed my permission
. It sounds like you are getting organized in the right way and have a good chance to start growing this year. Good for you!
We thought the process was to get 501c3 first, then go for MA Public Charity. This was the recommendation of the pro-bono CPA who helped us get through the processes. Our application for MA PC was basically a cover letter to the Atty Gen with the IRS 501c3 approval letter and a copy of the 501c3 application. I don't know if you can go in the other direction - get the MA PC done first then apply to the IRS. If you are aware of a MA PC application form, then I guess you can do it in either order.
I think most businesses - especially large, multi-state businesses - require the 501c3 to make a donation. So if you want to get donations from them they want to see the 501c3 rather than the state forms (in our experience). This also goes for avoiding state sales tax, they may want to see the ST-2/ST-5 forms but they also want to see the IRS approval.
You are not required to apply for 501c3, however, even if you are incorporated as a MA Public Charity, you will legally be required to file federal taxes on what you raise unless you become a 501c3 Non-Profit. This is because you raise more that $5K (gross receipts) - below that the IRS isn't as concerned.
I think it is worth doing. Let me know your decision and if I can help you I'd be glad to.