How are you going to mow in places where your mower will not fit?
Size is good for productivity but only if you have places to use it.
I think a 32 to 36 WB is key as well. I might save the money for the larger mower but only buy it when you have the accounts to support it.
It will take some time but you should be able to gross 2K per week fairly quick.
If I were you I would future plan more how to transition from the solo to the guy running a crew.
I like the 4 day schedule for routine maintenance