I have had the same dilema and know lots of others have too. I just use a big d shackle in place of the towball to tow from. I have seen some work mike has done for penetrator using the standard towbar mount but using a new tounge with a rated hook and a shackle hole in it. The other option is to go the whole hog and built a complete new rear bumper that has shackle hangers on it with a removable hitch like http://www.sonoransteel.com/Customers/Maryland.jpg
Go and get a heavy duty rear replacement bar made up with a centre mounted tow hook and shackles fitted where the bar attaches to the chassis. The centre hook you use for towing/snatching, the shackles you use for winching to evenly distibute the load.