What do you think of this one? (Standalone HDV hard drive recorder)
 

Hardware features

- Standalone HDV hard drive recorder/converter with
Real Time image enhancement and digital conversion
- Removable hard drive
- Front and back inputs for FireWire
- DVI and VGA outputs
- S/P DIF coaxial digital audio output, analogue stereo
output, both active
- DVD Reader for future software updates and
installation of additional hard drives
- Mini-Keypad with one-touch functions for record,
playback and more
- Records 23 hours of HDV material to the 250 GB
hard drive

Could it record real time, while shooting with XL H1? Have a look: http://www.hdvrecorder.us/

See the discussion in this thread: http://www.dvinfo.net/conf/showthread.php?t=61799