I have the pro comp coil spring conversion with some modifications. I am interested in going to a long arm setup with heim joints. Any recommendations for type of heim joints, size of tubing, where to buy the hangers for the frame etc. I was thinking of fabricating a "Y" link setup with one arm adjustable on the upper arm for pinion angle.

what Jeep are you talking about? I am assuming a YJ :) Check out RE joints, Blue Torch Fab (BTF) has some killer stuff, and fabrication parts taht you will need. Definitely document this stuff if you can, on how you did it. There was a good write-up somewhere of a similar setup, but with the Black Diamond coikl conversion on a CJ, to long arms I believe.

Gui

this is on a YJ using pro comp csc kit.

I will fully document and provide pics as well when completed. Perhaps even to work past some serious issues with the pro comp kit.

I recommend at teh same time dumping the pro comp springs, and possibly looking into Grand Cherokee Springs at the same time. On the front, a lot of issues in my buddy's Pro comp setup, steering interfering, etc. on the rear not that bad.

You might want to think twice about the Heim joints.
Unless this is an off road vehicle only, you will regret it. The heim joints will transmit all of the vibraiton to your frame.
As far as I know, Heim joints offer no advantage over good rubber...except for bling value.