Billing by 'teams' & 'seats'

I'd love a little steer on Spark (team) billing 'best practice': (using Stripe)

I want to have 4 plans, each has an increasing 'maxTeams' and 'maxTeamMembers'. These are a fixed price for monthly/yearls billing regardless of how many 'slots' filled.

Then a 5th 'ultra' plan that has unlimited users and teams, billed per team AND per memeber WITH a minimum fixed price (highr than the other plans)

Is this style of billing mix even possible? (out of the box)

Should/Could/How Would... I set up the 4 plans as a fixed price then the 5th as a per unit price of £team + £member? (assuming £teams != £members)

I'm guessing Stripe unit pricing come in to play here too.