I'm another vote for two screens. My setup is slightly different.
I have a home PC with a Dual Display. The monitors are 19" Eizo Flexscan, they are 16 years old but still Quite Good, I don't think they owe me anything and I'd likely replace them with two of similar size and quality if one went, although maybe nothing like that is still available, I certainly prefer the 4:3 format to widescreen. They have VGA and DVI input, driven from one card on my Windows box. Then, I have a work laptop on a stand, so that the screen is level with the middle of the other two. I use an Eizo front switch bezel to switch the middle monitor between home and work PC (connected via an HDMI-VGA lead) and that works fine. I quite like the resolution on the Eizo being "lower" so all I have to do to enlarge is to drop a window from the laptop onto it, but the variable ratios works ok most of the time but I like and would recommend the dual monitor display being the same on both, unlike the OP.