I've got a spare 500.4 and a spare 800.1 but I'm keeping them as they are in pristine nick and the prices are going up for them now Would hate to sell them and then regret it!
My last install was done 50/50 by me and a mate who happens to run an audio shop So he was doing it for me free of charge but helping me out where my knowledge let me down.
I'd have never been able to get the amp rack and sub box right without him, and same with wiring the dvd screen into the ai net output from the hu, would not have managed it alone.