just buy the one you like, and learn to ride it, don't compromise
and of course, test ride first, but you'll definitely need a B-full

my opinion, don't waste time/money on a 250cc anymore if you travel that distance to work

learn emergency maneuvers, like evasion and defensive riding
bigger bike is less about controlling the power unless you open the throttle quickly, but more about reducing emergency scenarios

at least you sound sensible, not the type that thinks "i can handle anything thrown at me"

CB250R = gegar telur, I suggest you skip this one, you might find it weaker than the RS150R