Look into a World Lawn 28" or 32" mower, the Timemaster won't last more than a few seasons if you buy the residential. You can get a World Lawn for only a few hundred more than the residential model. You have to think about the long term, if your going to stay in business you need to use Commercial equipment.
Most guys use a 21/22" and a 36" mower for small yards. The issue with a 30 inch mower is that it may not fit into some of the small gates.
There is an Old Blue Chair for each and every one of us, we just have to find it.
2006 GMC Sierra 2500hd crew cab
BOSS 8'2" Power V
Hustler X-one 60"
Toro Proline 36" wb w/t-bar controls
JS46 22" walk-behind (wouldn't recommend)
Shindaiwa T254, Echo trimmers, chainsaws, pole hedge trimmer, pole saw, hedge trimmer
Shindaiwa 633 and Husqvarna 130BT blower