It sounds like you are looking for a "do-it yourself job". Everyone has their own opinions and their own budget but this is something that I would recommend sending out to a gunsmith. You will be much happier putting a premium benchrest grade barrel on your gun than you would be just screwing on a factory replacement (better accuracy, faster cleaning, and longer barrel life). A gunsmith will be able to get everything square to 0.0005 inches or less, use the bolt you have by putting on a lathe and opening the bolt face to accomodate any size case that you want, and you will be able to specify your own barrel taper, length, finish, diameter... and create a unique gun. I have stated on other posts in this forum that I can HIGHLY recommend Hollands Gunsmithing in Powers, Oregon (www.hollandguns.com). This will cost you around $600 and you will wait about 3-4 months to get it back but you will not be disappointed. By the way, you can send guns via UPS without any problems or hassles if you are sending them to a licensed gunsmith.
Just think about how much it would cost you to do this yourself: you have to buy the barrel, buy a new bolt, buy the headspace gauges to make sure the gun is safe enough to shoot, and buy a barrel vice and removal tools...