I fabricated my first reinforced subframe myself before there was good information on how to do it (I made it WAY to beefy) - the next time I bought one from a group buy.
BAT has offered a new reinforced subframe for some time now, but at nearly $400 it is pricey, most of which is the cost of the new Ford part.
BAT Reinforced Subframe Your best choice is to have your existing subframe welded locally - assuming it is not tore up.
Your worst choice is to do nothing. With a 21mm bar you will tear the brackets loose regardless of how gentle you drive. Eventually you will have a wheel hit a rut or an unexpected pothole or something to stress the brackets. It doesn't take driving at the limit to cause damage - just driving on the street will eventually do it.
