My experience is that Holacracy is a great tool for a team of 4 people but I would agree that getting some external support would be valuable. I am currently supporting a team of 4 here in the UK to implement Holacracy. I'm providing a light level of support as they are essentially self-implementing Holacracy but some guidance along the way has been invaluable for them.
Online support works really well and of course there are plenty of resources (like this forum!) to help you along the way. Don't be put off from beginning this adventure. There is enough collective support globally to help make Holacracy really work for you if you guys are committed to making it happen.
I'm on firstname.lastname@example.org if you'd like to book in a time to talk,