Those criteria pretty much eliminate all guns.
You will not be able to get all of them. The price requirement pretty much totally sinks you.
Springfield Armory makes a Target 9mm Loaded 1911 with an adjustable rear sight. However, this is a full-sized all-steel 1911 that will nearly double your weight criteria and add another inch to the barrel. But you'll get the single action, and it comes I believe in stainless finish only, so no two-tone.
They also make the EMP, which is two-tone, single action, and meets your weight requirements. But again, no 4" barrel, no adjustable rear sight, and the fiberoptic sights would have to be added aftermarket.
Dan Wesson makes the Guardian 9mm, which might just squeak by the weight requirement, has a Commander-length 4.25" barrel, and is single action. But it only comes in black, does not have adjustable sights, and comes stock with tritium sights instead of fiberoptic. It is also double your price limit.
CZ meets a couple of your requirements... metal frame, some single actions, some with adjustable rear sights, some two-tone, but those that are have nearly 5" barrels, no fiber optic sights, and are $1000 or more. The ones that have 4" barrels and come within your price range are DA/SA with fixed sights.
You're probably SOL.