All of my bikes have swept bars. So far I've used the following kinds with success:

Velo Orange "Tourist"
Origin8 "Citi Classic"
FSA "Metropolis" -- larger clamp diameter
Generic steel swept bar from old Schwinn

I found it to be an effort to look through web sites for dimensions. Nitto makes a bunch of styles. I like them wider, but not crazy wide like some of the new MTB bars. An important spec is the length of the straight sections on the ends, to accommodate your hand grips and any other controls.

You can use the interrupters. One bike in the family fleet has them. There not as comfy as regular brake levers.

Some folks find the steel bars to be more comfortable due to having a bit of flex, and they won't add an unreasonable amount of weight. Steel / aluminum might be the difference you're seeing in prices.