Man, the card you're looking for is a cheap GeForce 2MX 200 or even a MX400. If you don't game, this card rocks for it's great performance/price ratio.
It's 2D performance is very good even on 19 inch monitors, it supports all important modern APIs (OpenGL, Direct 3D), it has very good drivers for Windows and Linux (including of course, a x-client from nVidia). If they pretend to play a old game the MX200 will rock too.
I know that the Matrox G-400 and up are better 2D performancers, but in reality, for Web surfing and Office programs, even on 19 inch monitor, there's no visible difference - for most people.
My opinion: buy him a cheap (but good) MSI or SOYO KT-133 with Savage 3D video and sound (both onboard). Pair it up with 256MB SDRAM, a Duron 900+ processor, a 20-40GB HD and a LG 16X burner, a Realtek 10/100 NIC, install Win2K Pro, and you're done. Really, a AMD Athlon XP 1700+ w/ 256MB DDR with a KT266A board for WEB SURFING and OFFICE Aplications it's just a waste of money and computacional power. I bet if you build both systems (my config and yours), your brother will NOT find any differences between them. I BET =]
But the price difference will be noticiable... =]