You mention existing client bases and healthcare.
Suggestion: You be the owner, let the experts do the healthcare. I'll explain.
I have, for a very long time, wanted to start a co-op/business that capitalizes on a somewhat booming sector. My idea is to buy/rent/lease a large warehouse/office space building. I'm thinking like a former HVAC supplier with 10 offices, a small warehouse, and flex retail space. You know, like when you walk into a larger Grainger, Fastenal, or Commercial building supply house.
I would start filling it with (wait for it and laugh later) new-age-ish things and some of the more progressive health care things. Yoga studio, licensed mental health counselors, head shop, chiropractors, massage therapists, salon/beauty/nails, spa treatments, essential oils shop, reiki studios, juice/coffee bar, maybe a vegan deli. The larger flex space could also be a real money maker. Hold seminars, have some of the experts like Yogis and reiki masters hold larger group seminars. Bring in outside talent; anything from fire dancers to psychics, DJs, alternative music groups, healthy cooking chefs... the list is endless.
And the seminars (in my dream) wouldn't have to be about new-agey stuff. The whole point of the new-agey spiritual ideals are self-love and self-sufficiency. I would straight up hold a seminar on teaching non-mechanical type hippie people how to change oil, or homeowners simple plumbing. Whatever skills people have to share to empower people in whatever they do.
In my original plan (when I lived in TX) my future partner in this scheme was a boat builder. He was hoping to give an ongoing boat building class where people could come in and build their own sailboats and then go sailing as a group. Sign up whenever, here are the materials and plans, he would mentor and help, and once a month those who had completed their boats would go to Town Lake and sail.
In my example, I practice Reiki and I'm (slowly) getting my master's in clinical counseling, but it doesn't take any of that to own the building and contract out tenants who fit the bill. Sit back, get free chiropractic adjustments and Yoga classes from your tenants, collect rent checks, and hire a general manager who has the smarts in that genre.