[ableal]

I just use the external 24 (or 25) inch display, and turn off the laptop display. I paid a bit more for 1920x1200 pixels, not the 'HD-TV' x1080 screens they're selling more of nowadays.

I also found simple plastic laptop stands with USB hubs. Plug regular keyboard and mouse into stand, shove stand+laptop to the side. As good as a desktop machine, plus it suspends with the lid shut.

As for the 'second screen', I just use multiple desktops/spaces. Less aggravating than switching screens, unless you really, really, need both visible simultaneously. Linux works fine, Mac seems a bit weak on moving windows around. Dock or 2nd Gnome toolbar on the side.

P.S. My local IKEA had on exhibit a good DIY monitor stand. Made by screwing 11cm Capita legs onto an Effektiv file frame front 80cm wide. I built a couple of those - they're great to place the display and laptop, with space to shove the keyboard and whatever underneath. (Sorry, no URLs, seems IKEA now thinks you have to login to browse the catalog - news to me.)