I'm going to be a little non-PC but here's my two cents. Not specific brands but in general.

Malipsitz at 155 pounds any bike is going to be more durable than it would be for larger folks. You don't have to worry so much about wheels, or whether your tire is big enough, or that the crank's going to bend. Flex isn't the issue that it can be with 200+ pound guys and track sprinters. So you have more feasible choices. I would operate under the assumption that the frame (ie, "brand") isn't that big of a differentiator at that price range and select based on a minimum level of components. Which on a single speed would be the rear wheel and hub, brakes, headset and bottom bracket (I guess, I'm not into the single-speed scene). Something to think about, lower end single speeds can be heavier than you'd expect compared to stripping parts off a decent road bike. Shimano components are good, even at the low end.

I'll be non-pc about the fenders and rack also. They are convenient, but not necessary if you'd rather keep them off your fast road bike. I'm that way myself and it isn't a hardship.