Running A 4/6 Screen Environment

Basically my question is, what's the best way of running a 4/6 screen windows 7 environment?

The detailed question is:-

I've just got a Dell XPS 8000 with a Nvidia GT 220 in it.

I'd like to run at least 4 19 inch screens. On my previous system (XP Pro 64 bit) I added a second PCI graphics card, which allowed me to run the 4 screens.

It's not for gaming, it's for developing, so I just need a lot of desktop real estate, more than 3D rendering power.

(Btw, I went for win 7 pro, due to the XP Pro Virtual machine, allowing me to run the 32bit cisco VPN client I need, in a 64 bit environment).

I installed the old PCI card I had a Nvidia GeForce FX 5200, but this seems to cause an issue with the GT220 card and the device manager reports it's stopped working (error code 43. I've googled it, seems a pretty generic error code, from what I can tell I think it's installing xddm drivers, which is the problem with wddm driver needed). I remove the card it BSOD's windows is unable to repair it, and I have to go back to a system restore point.

I see I have 2 spare PCIe x1 slots and a PCI slot on my motherboard.

Any suggestions?

Ideas I've toyed with are

1. Buy a PCIe x1 graphics card, possibly a quad card(but which one, nvidia or non nvidia)

2. Buy another PCI Graphics card,possibly a quad card( again which one? )

3. Can I spilt the HDMI and DVI outputs to give me 4 screens of 1280x1024. (or even 3 screens)

4. Scrap the GT 220, buy a PCI x16 card, then get another dual PCIe x1 card.(going to be very expensive I think).