I would also recommend Simon at SiFab for both.
The brake reaction bars are easy enough to fit, but mind the very fine thread at the top of king pin as its easy to cross thread if you're not very careful.
The Panhard rod is also simple to fit but space is very tight on the 4/4, clamp it in position first and check all clearances, I had to juggle mine to find the right spot.
Check twice and twice again, then drill once
