Thinkpad T430,
+1600x900HD screen upgrade
+All function keys are compatible with all major distros of linux
+Best keyboard on a 14-13 inch I have used
+Upgradeable battery lasts 8-9 hours(in text editors/browsing the web)
Avoid System76 if you need battery life, which was the main reason I chose the T430 over the Gazelle
I'll second the T430 series. I've had good luck with the T430u with the base configuration and ubuntu. Ubuntu installation was simple using a bootable USB drive and the latest Ubuntu desktop.
The screen on the T430u is not full HD, but cheaper than the regular T430 though.
I believe an SSD is available as an upgrade, but I suspect doing the upgrade yourself would be easy. I upgraded the RAM to 8 GB, which was an easy upgrade following the manual. The hard drive looks to be similarly easy to upgrade.
The keyboard is acceptable and I have found that I have adapted to it quickly.
I haven't pushed the battery life, but I would estimate 4-5 hours with web browsing and the screen brightness up.
I too upgraded the ram, just have to find one with the same timing on Amazon and pop it in(4gb stick). And as for the SSD I got myne on Newegg for $85 (128gb Samsung 840) also very simple to put in, remove a screw pull out the old and mount the new.
Avoid System76 if you need battery life, which was the main reason I chose the T430 over the Gazelle