With out seeing the springs, its hard to judge if its OK or not, I would get it to a local alignment shop or spring shop that deals with older vehicles. Don't expect a Wal-Mart oil changer to know what a leave spring is!
As far as changing them, its pretty easy other then the weight, 30 to 40 lbs each. The u-bolts will be tight, but should come off with some pre-soaking. The end bolts usually come out if they have been greased regularly. None of these require special tools or even that big of a tool, you might need a piece of pipe on the end for leverage, but thats about it. Once the front tires are off the ground, all the spring tensions is removed so they are safe to remove.
As far as new ones, I paid a little over $200 each for my '37 truck front springs. Shop around, prices vary a lot. The link section above has a lot places to check, try local first, it will save you some shipping money.
You are right about changing both at once, same for getting them repaired, both should be done at the same time. You don't want one stiffer then the other.
Joe
