Unfortunately, your small dell 8300 really restricts your upgrade abilities in a multitude of ways: physical space, the fact that the motherboard only has 1x pcie x16 slot and 3x pcie x1 slots, the dismal 460w PSU, and any heat related issues to cooling.
You can replace the GT530 and grab any cheap AMD eyefinity card (Sapphire 5570
, $55 AR) that will output to your first three monitors (instead of just 2) and then grab a pair of Zotac Ion pcie x1
gpu's for $60 a pop. This should be the cheapest and easiest solution of what your system can handle, but don't expect any miracles when running this system. Just make sure you plan out all of the video connectors and order the right extended cables for each monitor. I will tell you this right now. The included 3ft or 6ft length monitor cords are worthless in setting up 6+ monitor system.
Figure out what monitors you are going to use, then look for cables on meritline
. Depending on how you set them up (either in a row or use a fancy multi-monitor support stand), you'd need atleast 10-15ft cables on the furthest monitors. HDMI cables are usually the cheapest, but just remember, you are mixing dvi, hdmi, display port and vga. Its going to get messy.MaxPC did an eyefinity 6
build last year that showcases the custom stands better, but they are fairly expensive at around $400-500, but they will save your desktop space and provide you with more information at a glance without turning your head and loose precious time. That's the name of the game you are trying to play.
Personally, I would do one of two things: Sell this dell and recoupe money for a new PC build/give to a family member or harvest the dell for parts and upgrade the case, motherboard, powersupply and video cards. But that's just me.
In any way you put it, you have some work cut out for you and its going to cost you some moola.