Unless you will be towing in reverse it should not matter whether you install the subframe or the Kit.
The subframe should be able to handle anything you put that truck through. The wide ride kit is upwards of $2.3K so the economy of the subframe is a definate bonus unless the hot rod fairy left the kit under your pillow one night.
I know a Houston area welder who will come weld you up if you need a reference there. He did the subframe welding on my 54 after I did the fitting.
If I recall correctly he had a minimum of around $200.00.
