Sure, take a look at our S140-16. This looks like it could be a good match for your coil spring. This is compatible with either the 26-398 or 26-405. The better match depends on the hole spacing of your old pivot bar. Look ours over and see what you think.
All pricing can be found on each part's respective store page.
We have versions of the Series 140 with three springs, but they would be too strong for your window. The stamp printed on yours reads 16, which tells me that each balance on either side of your window is rated for 16 pounds. This is what our S140-16 is rated for, as well. It doesn't matter how many springs are used as long as they carry the same weight.
Most pivot bars only use one hole to install. As long as one of the holes on either the 26-398 or 26-405 match up to the hole you use then you should be okay.
When replacing pivot bars, the length isn't very critical. You want to focus on the distance from the tip of the pin to the installation hole.