cupped tires-lesser evil ?

greetings- we are talking about an '88 wagoneer limited with no lift-I have a vibration that gets worse about 55.I put new tires on in october-the front tires are now "severely cupped" says the guy who balanced them last week.the jeep has 210,000 miles on it and I'm sure everything in the front is worn out,although only a upper control arm at the axle was obviously shot-I tightened the bolt up and found the part numbers here today but have not yet replaced the bushings. running a tape across front and back of the front tires reads the same.so,my question is would a control arm being sloppy cause the tires to "cup"-and if not,what is the most common cause of this? rotating the bad tires front to rear put the vibration more in the seat and less in the steering but the vibration in the steering wheel is still there and reaches a worse point at highway speeds.there is also a tire noise from the front that I dont think are the tires ,if that makes sense.I couldnt feel any real movement when jacking it up to check bearings but agian,I'm sure everything is worn out-trying to fix the worst first. ideas?