Installing a GTX275 over a 8800GTX

In my current machine I have a pair of 8800GTX cards driving four displays one each per DVI output. I just picked up a newer GTX275 card and am wondering what is the best way to go about istalling it? I am assuming it best to uninstall my current drivers then remove both cards install the new card and download the drivers for it? Even if that is correct I have a few additional questions that I hope someone can help me with before I begin.1. I have my Nhancer settings per NickN's instructions I am assuming these can remain unchanged?2. I would still like to keep a single 8800GTX to drive two additional monitors is it possible or will there be a driver conflict? I know I have heard people runing disiliar cards in the past but this is new territory to me.3 Any driver recommendations for the GTX 275? My OS is Vista 64.Thanks in advance. I am a little limited on time so I am trying to minimize my down time as well as avoid as much frustration as possible.Thanks in Advance,Robert