I am using the ones on the left for my lowers.
http://www.suicidedoors.com/products...k_ends_200.htm
$10.00 for the bushings, sleeve and 2" x 2.75 x 1/4 wall D.O.M. tubing.
These are about as cheap as you will spend for a poly bushing end. Great quality also. I'll be using them with the bushings and sleeves modified for a 5/8th inch bolt instead of a 9/16th's.
I had thought about using another set for the uppers but I am going to end up making them I think. I would have to narrow them up a bit to fit the "G" body cross shaft and the shaft is 5/8th's of an inch where it goes through the bushing so the inner sleeves wouldn't work either. I will be getting some 2" O.D. x 3/8th wall D.O.M and turning the I.D. to press in a stock type shell bushing. This will give me a number of bushing options from stock rubber to poly/graphite and I think this will help in tuning...
Mark