I'll bet if you add up the cost to add disc brakes, springs, shocks, rebuild parts ect. you won't be far off the price of a new IFS. With the new IFS you get correct geometry for radial tires, power steering if you want it and coilovers.
I'm putting a Scott's Hot Rods IFS on my 38 right now. The Scotts front end is far superior to Fat Man, and less $$ then the big names. It's a big job, but if you can measure & weld it's doable. My car has a 67 318, and the next step is motor mounts.
If you do go with Scott's, be aware that their written directions leave alot to be desired, but they usully respond to emails or phone calls within a day.
I can give you alot of hard earned tips if you need them!