housejunky

I have a panel truck I'm customiseing and I know nothing about what I am doing. I am building a 390 to go ointo it and I want to know the best way to swap out the front suspension to accomidate the 390 add power steering and disk breaks. Can I swap it the front end for something out of a newer car or should I buy a front end set up from one of the guys who sells chassis and front end kits and how hard is this to do. Is it as simple as unboalting the old and boalting in the new or is there torches and welding involved. Also I want to do the same for thr rear end. Should I box in the frame as well?