Yes make sure you measure from flange to flange and on the same spots on both flanges (bottom of both, etc.)
Your more than likely going to need a long slip front driveline unless your linked in the front or really have no flex at all. You also may need to clearance the cv depending on your angles amd which cv you have.
Is this a rig that's goint to be trailered or street driven?
I ask because if you don't want vibrations I would have a shop do it. Sure you may get lucky if you do it yourself and have it be straight and not too far out of balance but that rarely happens.
Another thing is if you plan on doing it yourself you have to phase it when you assemble it (look it up if you are not sure). If you are reusing stock tubing it is thin an prone to ripping apart if you hit it on a rock so you may want to retube it with thicker tubing.when you layout the driveline before assembly your going to want to shoot for about 1.5 inches off bottom at ride height. And do not count on getting it straight unless you have some sort of apparatus to keep it consistant while you measure the runout.
There is a lot involved in making them vibration free.
