Hypothetically speaking of course, I don't think it would be any worse off than a T5-the new tranny will take what a new 5.0 puts out (390lb/ft), and although I don't haunt the new 5.0 threads, I haven't heard much about the trannys coming apart as of yet. That being said, I'm sure getting the transmission mounted in the car would pose some challenges even if you did have a bellhousing to mate it up, but probably nothing out of the ordinary. Mounts not immediately available could be fabbed, shifter holes could be cut to accomodate, despite the possibility it might not be compatible with your console. Driveshaft yokes could be adapted, etc etc etc.
I have an old Plymouth Scamp (A body) and the trans tunnel in those is kinda shallow, but there are scads of folks out there swapping in modern overdrive transmissions that necessitate sometimes extensive modification of the floorpans-to include the torsion bar crossmember. So, putting the trans in there is more a matter of having the time, patience, and parts to mate it all up. Fabrication can happen and save you money in the long run as long as you have the skill to make it all work.
While budget, 6 speed, and fox don't really go together, it would be nice to have availability of them, and he makes a point that since the parts are becoming more commonplace everyday Mustangs continue to be manufactured. I don't necessarily think Lakewood is working that type of adapter, but it might be kinda cool.
...just a thought.