It's really a question of how open your tank is.
More open space = more momentum that a pump can build AND fewer obstructions to create turbulence.
The more rock, fish, coral heads, etc you have in the tank, the more "dark spots" there will be in your flow.
Any flow pump like a Tunze Nanostream or even Maxspect Gyre will do a lot under favorable conditions as compared to a traditional pump like a MaxiJet or Rio pump....but there's only so much one pump can do. Eventually you find the limit and will need a second (and eventually third) flow source.
I think looking for a one-pump solution short-changes your design - especially past the short term (1-2 years or so).
Flowing a brand new tank is easy though, so one pump could very well do it for a while.
Personally, I'd always like to have at least two pumps for flow...
one for flood tide, one for ebb tide...alternating ON/OFF every few hours or so.
Again personally...for a 75 gallon, and longer term satisfaction, I think I'd rather have a set of Tunze 6045's. Four on simple appliance timers set to a tide schedule would be a great base that wouldn't break the bank. ($78 * 4 = $312):
A couple of 6055's would be nice as well, if controllable pumps are a must ($185 * 2 = $370):
...perhaps with a 6040 ($140) or two added to the mix:
You could even do all the flow with 6040's. Or maybe even one big 6150:
https://www.tunze.com/US/en/catalogue/katalog-ii.html?user_tunzeprod_pi1[predid]=-infoxunter054
Lots of good options.
