If you go Independent front suspension, you will have a weaker front end with no load carrying capacity. You will also need to change the rear axle so you can have matching bolt patterns on your wheels, so add in driveline , steering column, brake booster & master cylinder, tires & wheels, welding labor, and a whole bunch of small misc. stuff.
Rebuilding what you already have will be cheaper. Tie-rods and king pins are not that much money, and it's something you can do with not many tools. Springs can be pulled apart and cleaned for the price of a couple center bolts. Changing out the spring bushings is also a DIY project, there's a thread about it going right now in this forum. Rebuilding the steering box requires a couple gaskets and a couple bushings, there's even a online manual to walk you through it. Once that's done, the whole front is like new. Drive it for while and see if it really needs changed, if you are not happy, sell off the rebuilt parts and buy what you want, someone is always looking for original pieces.
