On the hardware side, there's an HDMI port; you can connect a monitor up to 1920x1200 (possibly through an HDMI-DVI or HDMI-VGA adapter, which costs barely more than an HDMI cable). There are 4 USB2 ports. The Ethernet port is 100Mbit/s, which should be plenty sufficient for a thin client, especially if it's displaying a web page rather than doing X11 over Ethernet. Wifi isn't built in; if you need that you'll need to get a USB wifi adapter. There's also a pair of sound jacks in case you need to plug in a microphone and loudspeakers.
The small form factor and low power consumption (far less than anything you could get with an Intel processor) make it appropriate for environments with dicey power. There's no battery, though you can purchase one separately.
The one downside I see is that the only form of storage is an SD card, which can be removed in an untimely manner. You may want to hold it in place with sticky tape or something.
There's only 1GB of RAM, not 2GB, but that's enough to display a few web pages.
The Pi has an ARM CPU. That means Windows is out (except a special version of Windows 10, but most Windows software won't run on it since most vendors distribute only x86 binaries), but almost all Linux software will work.
Ubuntu 14.04 doesn't officially support ARM but there's an unofficial image. If you prefer a distribution that's officially mantained, you can get Debian jessie (there's also Raspbian, but it's optimized for the Raspberry Pi 1, not version 2 which is what you should get now that it's out). Ubuntu is based on Debian and pretty much all the system administration will be the same. Debian doesn't ship Ubuntu's Unity interface, though¹.
Both Firefox and Chromium (not Chrome) run on the Pi. There are also more lightweight browsers; try them with your web pages and see if they support all the features you need.
The reference price for the RPi2 is $35, to which you'll need to add a bunch of accessories (USB power supply, keyboard, mouse, monitor, cables, USB wifi adapter if needed).
There are other similar ARM-based boards that may be more adapted to your needs, for example if 2GB RAM is a strong requirement, or if you really want Gigabit Ethernet, or if you need wifi, etc. The reason I'm putting the Pi forward is that it's the one with the most literature and support out there.
¹ This may be a relief.
