>> I feel like I'm less productive on multiple monitors. I've tried them a number of times, but they've never felt natural. I just prefer looking straight ahead, managing a single screen, and clicking between the few programs I'm running in the taskbar. Also, I like some room on my desk, and big monitor displays just seem overwhelming.

You might (maybe, just saying what I like) want to try one 'main' monitor and one subsidiary. Can be the same size or smaller. Main monitor is for the work you're focussed on, the other monitor is where you have documentation or other reference material you need while working. I quite like this pattern rather than just throwing programs all over the two screens.