Desperado JC... but I am concerned about your Hard Disc Drive requirement. Since HDDs have known issues with trying to record in high vibration environments and high altitude, there are not too many of them over about $1,300. The folks that get to this level know better. When the hard disc drive crashes, all the video on it will be gone - whether you transferred it to the computer, or not.
Flash memory camcorders record the same file formats as HDD in this price range. Basically, the Canon HF S series and the Sony HDR-CX500 series. The CX500 series has a 37mm lens filter diameter while the S 100 58mm lens filter diameter with a single (1/2.6" for Canon; 1/2.88" for Sony) CMOS imaging chip. Their lowlight behavior is OK - but not "great". If you need "great", then you need larger lenses and imaging chips and a bigger budget.
We don't know which version Apple Final Cut Pro you are using - or which Mac or which version OSX - so there is no way for us to know if the camcorders will be compatible with your particular environment. I have successfully used a HF S100 and HDR-CX550 with my Intel-chip based Macs and Final Cut Express.
The Canon HF S series and the Sony HDR-CX500 series have manual audio gain control and the gain control is accessed by assigning the single control thumbwheel on the outside of the camcorder that function. When the thumbwheel is assigned that functions, other manual functions that might be assigned to that thumbwheel cannot be used until you go into the menu and select the other function. Both series cams also have a 1/8" (3.5mm) stereo audio in port for external audio connectivity. Use of an XLR adapter (juicedLink or BeachTek - among others) is recommended if XLR mics are used. The added benefit is the XLR adapter can be the manual audio control. The Canon HV40 does 24 fps, is miniDV tape based, has manual audio control and a 1/8" stereo mic jack, too.
Skipping your hard disc drive requirement.
24 fps for the Canon; The CX500 series does not even have the fake "cineframe" many other Sonys have.
If "great" low light behavior is a requirement, then you start with camcorders that have lens filter diameter of 70mm or larger and imaging chips that are 1/3" (or larger) in a 3CCD or 3CMOS array. Basically, for high definition, the Canon XHA1 or Sony HDR-FX1000. Both are more than twice what you want to spend, record to miniDV tape - but can use external recording devices from Focus Enhancements' FireStore series (Sony has one for their cams, too). You can check on the 24 fps with these. There are others, these are merely the starting point for "great" low light behavior.
So... you get to either change your requirements or increase your budget.