I did a set a few years ago. Did the majority of it with a grinder and a sawzall. I took mine off in chunks then got smart and wsent for the weld. I had the cast ones welded to the tubes and they were a PITA. It is no easy task and requires alot of patience.
In regards to perches, I would go with what DIY sells or fab your own. A good idea if they are having extra height added to them is have them add 1/2" stell on the inside of it to reinforce the extra height. I bought a set from ORU and look what happened.
Luckily I was in the company of a good friend and an experienced fabricator and he made me a set of these
These are nothing more than box tube radiused to fit the axle tube, with 1/2" steel welded to the inside and the outside of the tube to strengthen them, plus allowed me to lose my zero rate too.