I myself consider it a big job to undertake,replacing rails.I would try and straighten the rail first,especially if its solid.
I have had some people whine about the $$$$ I charge for really good sheetmetal,but most that cry about the price have never removed this stuff at the spotwelds.I had a guy buy the cuda rear speaker deck that I removed($350)He sent me pics he was so happy with the way I removed it(all by hand,no air chisel)He set it in and all the spotwelds lined up with his cars and had it in,in 45 minutes.And my hands show the wrath of removing this stuff.So if you can fix the rail,I say fix it,or at the least give it a try.I have three sets of frt rails right now,so if it doesn't work?I am sure I can get you what you need.
The Clown