Help!

I can't decide between UMS 180 or 210.
I'm building a coustom T28 at 114in wing span around 45 pounds I'm hoping.

My issue is I'm limited to a 28in max diameter prop, preferably a nice scale 3 blade.

It seems the UMS site say the 180cc runs a 28x10 2 blade while Belia prop sales says a Moki 180 is suited for there 28x16x3 blade which sounds like a huge load difference.

But all the UMS210 are in the 32in range. But saw a video of a guy rocking the same 28x16x3 blade as a brakein prop but upgraded to 32in next video.

On speck sheet the 180 and 210 look exactly the same except the 180 is .2in smaller which I would prefer but i don't know which is better choice?

Thought?

one guy told me to get 210 and just limited max rpm on Ground around 4500 with servo, but then would the motor still pick up rom in air?

Thanks