If you're going to be sticking in a flashed drive, you might as well just flash the drive it came with. All drives except LiteOn can be flashed back to their original state, and there's no real advantage to selling it with original firmware in favour of custom firmware. It's simply easier and cheaper this way.
However if you still want another drive, you can take any drive and spoof it like the original drive using the original drive key. Once you have the drive key of the original drive, it's only a couple more clicks of the mouse to flash it with iXtreme anyway. When you spoof the drive though, you also have to spoof the drive firmware to make it "look" like the original drive. The Xbox seems not to like it when you stick in (for example) a Samsung drive when it originally came with a LiteOn. This is only one small extra step in the process though, once you have the original drive key.
Anyway, I'm lazy with linking guides and can just explain what I know. iXtreme 1.61 for Samsung and BenQ is currently the firmware you should be looking for, or 1.51 for Hitachi. If you've got a LiteOn, you only get 1.6. JungleFlasher is what I use for flashing most of the time and has always worked fine for me (along with the JungleFlasher tutorial on the site). If you have a LiteOn 7x drive, you will need a connectivity kit with a probe/spear to stick into the PCB (bought or homemade probe). If it's LiteOn 8x v2 or 9x, it will take a lot more effort. Basically, the newer the LiteOn, the more annoying it is to flash it.
Oh, and FYI, flashing the drive does not affect the motherboard at all, however iXtreme is detectable so don't try going online at any time with a flashed drive
EDIT: lots of posts whilst I was typing ;p