For the drivers do not use the ones from Dell. They are underclocked and pretty much garbage. You should use either Omega drivers or the official drivers from ATI. If you are going to use the official drivers from ATI than you will need to edit some of the files for them to work with the mobility card. Here is the link to the page that has a tool that will edit the files for you so you can use the official drivers from ATI.
http://www.driverheaven.net/patje/
ATI is upto 5.8 for the drivers but with Omega they are at 5.7. Omega has decided to skip 5.8 and just do them for 5.9 whenever he has them or something. But the Omega drivers are very nice and not a whole lot of a difference between the 5.7 and 5.8.
You can use ATI Tray Tools, or ATI Tool to overclock the card. Both of them have the ability to determine what your cards maximum core and memory speeds are. I use ATI Tray Tools simiply because there is so much more with it than ATI Tool. And Tray Tools comes with the Omega Drivers.
I hope this answered your questions. I am in the process right now of fine tuning all my clock speeds and stuff to get em just right. So just ask if you need anything else.
