Right now there is a huge hole between a Mini (M1) and a Studio (M1 Max or Ultra).
I for one am waiting and hoping the Mini gets updated to to an M1 Pro level, or equivalent.
So choices include (but are not limited to):
1. Get a refurb mid-spec 2020 iMac - you get a lot for the price, but it is not the future - expect to maybe upgrade again in several years
2. Get a Studio plus studio display for twice the price and is likely overkill
3. Wait and hope for an improved Mini, plus studio display
What you decide depends on budget, affluence, and how long you want to wait.
Other possible pairings include third party monitors (not as good), or a 14" MacBook M1 Pro (if you need a laptop anyway).
This is discarding dreams like a larger iMac.