As far as Ive been able to determine the best video card you can get for the Acer AX1420G-U5832 is the Radeon 6670 LP by either Sapphire or Powercolor. Both fit and both use minimal power, (around 60w max for the Sapphire or 75w max for the Powercolor) but you have to keep your driver downgraded to Catalyst 11.5b or the system wont boot. Im only running older games on mine but it runs Dragonage and similar games at max graphics settings and Ive seen reports that the 6670 will run most newer games on mid to low settings. http://www.pcmag.com...,2385800,00.asp
Just wanted to get the info out there as I couldn't find this info anywheres and had to figure it out from reading hundreds of reviews on sites like newegg
BTW the fan on the Powercolor version looks to be in the perfect place to draw air through the vent on the top of the case, haven't tried it myself but it looks like the perfect graphics solution for this system.
Edited by Zritter, 19 June 2012 - 04:20 PM.