Is there something wrong with the frame on your truck? If not, then I would simply box it up and put an IFS of your choice up front and a four link of your choice in the rear.
My roller is pretty much finished up now, and it has a camaro/firebird clip up front. I don't see where there is any width issue at all. The entire front end has been completely installed on it too. The reason I would go to an IFS if I could do it over again is because I love the clean, simple look of them. The full length straight frame rails are just more attractive to me than the curvaceous, modern looking clips patched onto the vintage frame.
Just thought I'd add my opinion, since I've been in your shoes.