You are on the right track by starting with a 36.
The ideal combo for a solo is a 36 WB and a 52 or 60 Z.
You can do a lot with the 36, I did it that way.
Now, you can use the belt drive but, you just don't know how much faster and easier the hydro is. It's like a quantum leap to me.
The power in a hydro is all weather, meaning, dew won't make the drive system slip. They hold hills much better.
Also, the ability to back up instantly is tremendous.
As far as Hustler goes, I'm getting 2 of the 36" next spring.
I have 5 WB's now, 32, 2x36 all 3 gear drive, 48 and 52 hydro.
Remembering all my departed friends.