I would suggest fixing the monitor of the force. Is it the radion (old tube crt) or the evo (flat lcd)
Anyway, you can mount everything from the force except the monitor (obviously) into the XL titanium cabinet. You will need to make a few brackets and buy some standoff screw mounts, or use the ones in the XL and force cabinets. I have donea few conversions like this. I even made a custom lcd faceplate to mount a 15 inch lcd in a XL cabinet and had 2009 ion software/parts running in it.
One note, if you use the XL monitor (13 inch) you will be forced to run only games in low res mode. (640x480) Im pretty sure low res mode is default with 2006 software. I believe 2008 or 2009 low res was no longer default. or the option was removed, its alittle fuzzy, been awhile since i did the conversions and played around with the low res settings.