Hi, and WELCOME TO TECHIMO...!
I haven't heard of anything that would do what (it sounds like) you want, but you have confused me somewhat with the comment about using both displays - after saying that you 'have a 23" widescreen', and also why you would want/need to have that setup when you have multiple screens available, but never mind....
You could size the windows to meet in the middle and spread over to the edges, but this won't force everything to use the same size windows.
I'm sure that someone else on here will have a better idea, but unfortunately that's as far as I can help you on this....
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