I should of clarified - the PCI-e 1x slot is meant to be a PCI-slot replacer (although it's failed because nothing really needs the bandwidth), the PCI-e 4x/8x/16x slots are all the same and you can usually change the speed in the BIOS (why you would i don't know).
For a 6200 you could probably use a 4x slot, as it's got very little power.
The problem with running 2 cards is that often the cheaper (i say cheaper, but i mean not ultra expensive) boards don't have the bandwidth spare, and when you use 2x cards they go from 16x in a single lane to splitting it to two 8x lanes. It's worth checking this on the internet, as my board goes from a single 16x lane to a 16x and a 4x lane (which makes it pretty useless for Crossfire).
I can't recommend a motherboard, because i'll end up making you spend £150 on a nice x38 overclocking board, the eVGA 650i gets good reviews, but i couldn't seem to find what it becomes when put in SLi mode.
Of course, 8x won't make that much of a difference to the performance, but it will make the difference between a GTS and a GT a lot less noticable.
) the 650i that I'm looking at is not an SLI board and has one (1) PCIe 16x slot which will take my main graphics card (most likely a 8800GTS 320mb or 8800GT if they come out in time) and two (2) PCIe 1x slots, which would take a 6200 for this use without affecting the speed of my main graphics card. I assume Windows will also support a third monitor on a second graphics card for an extended desktop as well?
