I cross posted this over on 924board.org, and there are some interesting opinions posted over there regarding the viability of this approach:
924Board.org :: View topic - X-Post: Custom A arms
Anyone considering these would probably be advised to read thru and consider some of the concerns expressed there. It would also be nice to hear from the creator regarding the concerns, and also to understand why $20 in used car parts with a piece of steel bolted onto the end justifies the $700+ price tag.
I'm not taking sides one way or the other. I still find this to be an interesting approach, but I think there are some important questions yet to be answered.